Takashi Tanizaki
email: tanizaki@hiro.kindai.ac.jp

Optimum Arrangement of Taxi Drivers' Working Hours

Keywords: optimum arrangement, mathematical model, taxi company, staff scheduling, Weighted Constraint Satisfaction Problem

We propose optimum arrangement of taxi drivers' working hours. In Japan, income of taxi vehicle is decreasing about 11 thousand yen in the past 15 years. Then some taxi companies are investing to gain more customers. But there are many small taxi companies that are difficult to invest with much money. Therefore we have been researching the other method to gain more customers by little investment for small companies. In this paper, we analyze present situation of the Taxi Company which we research, research optimum arrangement of taxi drivers' working hours so as to increase sales amount using mathematical model, and verify validity of our method with numerical calculation.

Introduction

Financial condition (ex. Income of taxi vehicle per day) of taxi companies in Japan from 1995 to 2011 is shown in Fig. 1. The annual number of customer is decreasing by about 800 million people, the annual transportation income is decreasing by about 860 billion yen, the number of taxi vehicle is decreasing by about 13 thousand cars, and income of a taxi vehicle per day is decreasing about 11 thousand yen. It is thought Fig. 1. Financial condition of taxi companies [START_REF]Infrastructure, Transport, and Tourism: About the present condition of national taxi enterprise[END_REF] 26 that this factor is in the collapse of the bubble economy and the failure of Lehman Brothers. Then taxi companies introduce various methods to gain more customers. Some companies begin to introduce new taxi operation system using GPS and smartphone to shorten taxi waiting time. But there are many small taxi companies that are difficult to introduce above system. So we have been researching the other method to gain more customers by little investment for small companies as follows [2][3].

 Rearranging taxi drivers' working hours using computer simulation so as to work many taxis with many taxi delivery demands by telephone requests.  Optimum allocation of standby taxis at taxi stands so as to minimize total millage between taxi stands and the place where customer takes a taxi.

In this paper, we analyze present situation of the Taxi Company which we research (we call Company A in this paper), research optimum arrangement of taxi drivers' working hours so as to increase sales amount using mathematical model, and verify validity of our method with numerical computation results.

Present Situation of Company A

Taxi Drivers' Working Hours of Company A

Taxi drivers' working hours according to service pattern of Company A is shown in Table 1. Taxi driver's service pattern consists of four groups, such as Shift, Day, Fixed time, and Night. Details of each service pattern are described in [START_REF] Tanizaki | Improvement Method of Service Productivity for Taxi Company, Advances in Production Management Systems[END_REF].

Table 1. Working hours

The sales amount of Company A

We get sales data between 2011/12 and 2012/11 from Company A. We calculate average sales amount according to time by the day of the week shown in Fig. 2, by week shown in Fig. 3, respectively. Average sales amount values are normalized so that the minimum value is equal to 1.0. From Fig. 2, the characteristics of average sales amount are as follows.

 Fhe sales amount differs by the day of the week. The Sales amount of Friday and Saturnday are high. That of Sunday is low.  The sales amount according to the week is the almost same.  The sales amount from 8:00 to 9:00 and from 17:00 to 24:00 is high, from 2:00 to 7:00 is very low, from 10:00 to 11:00 and from from 13:00 to 16:00 is low.

The sales amount is different depend on time and the day of the week. We research optimum arrangement of taxi drivers' working hours so as to increase sales amount using mathematical model.

Formulation

There are differences in the sales amount by time, the day of the week. This reason is because the number of customers and the taxi operation number vary according to time and the day of the week. Therefore we research optimum arrangement of taxi drivers' working hours so as to increase sales amount using mathematical model. Basic idea for arrangement of taxi drivers' working hours is putting the belt of continuous working time in the day under the following constraints (Fig. 4).

 Taxi drivers must work working hours for each service pattern continuously.  Working hours for every service pattern is the same every day.

Notation

The following notations are used to formulate this problem. i:time zone (i = 0, 1, 2, …, 335) j:service pattern (j = 0, 1, …, 7) 0; Shift 1, 1;Shift 2, 2;Shift 3, 3;Shift 4, 4;Day, 5;first half of Fixed time, 6;second half of Fixed time, 7;Night C i :Sales amount in time zone i C i is calculated as follows N ij ;The number of taxis which can work in time zone i for service pattern j T j :Continuation working hours for service pattern j x ij :0-1 integer variable which denotes taxi operation in time zone i for service pattern j 1 (working) x ij = 0 (not working)

Formulation

The objective is to maximize total sales amount. Problem is formulated as follows: (n=1,2,…,13).

∑ ∑ . ( 1
) Subject to ∑ , (2)
∑ , (3)
∑ , ( 4
(5) Constraint [START_REF] Tanizaki | Improvement Method of Service Productivity for Taxi Company, Advances in Production Management Systems[END_REF] shows that at least one service pattern "Shift" exits in each time zone. Constraints (3) and (4) shows service pattern j continues T j hours. Constraint (5) shows taxi operation in each time zone is the same every day.

Solution method

This model is nonlinear programming problem. It is difficult to calculate the optimum solution in short time. We reformulate the problem as Weighted Constraint Satisfaction Problem (WCSP) because variables are 0-1 integer, and solve WCSP by taboo search. WCSP is a problem which assigns a value in order to satisfy important constraints as much as possible [START_REF] Nonobe | Development of general purpose solvers by meta heuristics[END_REF]. In WCSP, the importance of constraints is set up as weight parameter. Therefore it is possible to calculate solution in which the model maker's intention was reflected about the sufficiency condition of constraints. An optimization problem is formulated as WCSP by changing objective function f(x 1 , x 2 , ⋯, x n ) into the constraints introducing the target value μ as follows:



∑ ∑ (6)

WCSP will end calculation, if one of the following conditions is satisfied.

(1)The solution which satisfies all the constraints is solved.

(2)The specified iteration count is exceeded.

(3)The specified computation time is exceeded.

We choose (3) and computation time is made into 3600 seconds. The solution procedure is as follows.

Step 1 Set up of computation time.

Step 2 Set up of target value μ.

Step 3 Solve WCSP using taboo search.

Step 4 When a solution comes out within computation time, a target value is increased and back to Step 3.

Step 5 When it exceeds computation time, calculation is ended. The solution at the time is adopted.

Conclusions

We research optimum arrangement of taxi drivers' working hours to gain more customers by little investment for small companies. For the above purpose, we analyze present situation of Taxi Company A using sales data, and formulate mathmatical model so as to increase sales amount. This model is nonlinear programming problem and difficult to calculate the optimum solution in short time. Therefore we reformulate the problem as WCSP, and solve WCSP by taboo search. We verify validity of our method with numerical computation results. As a result, it turns out that it is effective strategy to reduce the number of taxi operation in time zone of low sales amout (9:00 to 16:00) , and increases the number of taxi operation in time zone of high sales amount (18:00 to 0:00).

Fig. 2 .Fig. 3 .

 23 Fig. 2. Average sales amount according to time by day of week

Fig. 4 .

 4 Fig. 4. Example of working hours



  In case of Minimization problem ⋯ In case of Maximization problem ⋯ An objective function is treated as soft restrictions. Although soft restrictions must not necessarily be satisfied, they are satisfied as much as possible. In our problem, objective function (1) is changed constraint (6) in WCSP.

4

The application result to Company A

Numerical computation case

We calculate quasi-optimum solution using procedure in chapter 3. We compare the solution result of the problem in chapter 3 and the problem added constraints including heuristics to which sales amount may become high based on data analysis. Company A requests us to study the new service pattern which become the sales amount high not adhering to the present service pattern. Therefore we compare the solution result of the problem added the constraints with new service pattern (Table 2).

 Pattern 0

[Method] Solve problem in chapter 3.

[Purpose] Calculate quasi-optimum solution, and compare with the present condition  Pattern 1

[Method] Add the constraints which change working hours "Fixed time".

[Purpose] Increase the number of taxi operation after 20:00 with high sales amount.

 Pattern2

[Method] Add the constraints which divide working hours of "Fixed time".

[Purpose] Increase the number of taxi operation after 20:00 and decrease the number of taxi operation between 14:00 and 16:00 with low sales amount.

 Pattern 3

[Method] Add the constraints which change the day of the week of "Fixed time".

[Purpose] Increase the number of taxi operation on Friday and Saturday with high sales amount. From 9:00 to 23:00 3

From 10:00 to 0:00 4

From 11:00 to 1:00 5

From 12:00 to 2:00 2 6 From 7:00 to 14:00, From 17:00 to 0:00 7

From 8:00 to 15:00, From 17:00 to 0:00 8 From 8:00 to 14:00, From 18:00 to 1:00 9

From 7:00 to 13:00, From 16:00 to 0:00 10 From 8:00 to 14:00, From 16:00 to 0:00 11 From 8:00 to 14:00, From 17:00 to 1:00

Computation results

Numerical computation results using sales data between 2011/12 and 2012/11 from Company A is in Table3. The annual sales amount of case 17 of pattern 3 is the highest. On the whole, the sales amount of the pattern 3 are high. Furthermore, it is a result of the tendency which reduces the number of taxi operation in time zone of low sales amout (9:00 to 16:00) , and increases the number of taxi operation in time zone of high sales amount (18:00 to 0:00). We get some hints which consider new working hours as follows.

 The number of taxi operation from Monday to Thursday is reduced, and it from Friday to Saturday is increased.  The number of taxi operation from 9:00 to 16:00 is reduced, and it from 18:00 to 0:00 is increased. 7:00 20:00 base 15 1:00 2:00 3:00 8:00 19:00 4:00 0 8:00 12:00 6:00 6:00 18:00 20:00 106.0% 5 2:00 7:00 1:00 2:00 6:00 4:00 1 2 8:00 8:00 7:00 17:00 14:00 17:00 102.3% 13 2:00 2:00 2:00 13:00 2:00 1:00 3 3:00 7:00 7:00 8:00 14:00 13:00 99.2% 16 21:00 1:00 2:00 4:00 2:00 21:00 4 8:00 16:00 8:00 8:00 15:00 20:00 105.9% 6 2:00 10:00 3:00 4:00 3:00 4:00 5 7:00 14:00 1:00 5:00 17:00 23:00 105.5% 9 1:00 8:00 20:00 1:00 5:00 7:00 6 19:00 7:00 8:00 7:00 15:00 7:00 17:00 19:00 105.7% 8 13:00 1:00 3:00 3:00 3:00 14:00 0:00 3:00 7 8:00 8:00 8:00 16:00 8:00 8:00 17:00 18:00 101.9% 14 2:00 2:00 3:00 12:00 20:00 15:00 0:00 2:00 8 9 8:00 8:00 7:00 13:00 13:00 7:00 16:00 19:00 103.8% 11 2:00 2:00 2:00 9:00 1:00 13:00 0:00 3:00 10 15:00 8:00 10:00 7:00 14:00 8:00 16:00 20:00 105.9% 7 9:00 2:00 5:00 3:00 2:00 14:00 0:00 4:00 11 5:00 9:00 9:00 1:00 14:00 8:00 17:00 15:00 102.4% 12 23:00 3:00 4:00 21:00 2:00 14:00 1:00 23:00 12 2:00 20:00 8:00 16:00 20:00 15:00 107.7% 2 20:00 14:00 3:00 12:00 8:00 23:00 13 14:00 22:00 6:00 4:00 14:00 7:00 106.5% 4 8:00 16:00 1:00 0:00 2:00 15:00 14 15 0:00 7:00 14:00 23:00 15:00 20:00 104.9% 10 18:00 1:00 9:00 19:00 3:00 4:00 16 8:00 8:00 11:00 5:00 18:00 20:00 106.7% 3 2:00 2:00 6:00 1:00 6:00 4:00 17 7:00 10:00 21:00 6:00 16:00 20:00 108.7% 1 1:00 4:00 16:00 2:00 4:00 4:00 2:00


Joakim Wikner
email: joakim.wikner@decouplingpoints.org

Supply Chain Management Strategies in Terms of Decoupling Points and Decoupling Zones

Keywords: Decoupling points, segmentation, leagility, customization, postponement, servitization, closed-loop, outsourcing, visibility

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Several concepts related to strategies for production and supply management, hereafter referred to as supply chain management strategies, have been developed over the years covering a wide range of scenarios. As the market requirements change the concerned businesses have to evolve to stay competitive. Through this process the concept of supply chain management (SCM) has become fragmented and created a need for a more knowledge on fundamental properties that are shared between different concepts and strategies. A monolithic approach to SCM covers a wide range of issues that are complex and challenging to handle simultaneously. The decisions involved can be categorized from a transformation perspective into a three layers as suggested by Wikner [START_REF] Wikner | On decoupling points and decoupling zones[END_REF]. At the company layer a legal perspective is dominant since this involves the issue about who is actually the sponsor of the transformation. This is the layer where the financial transactions are in focus. The financial transactions are however a consequence of activities being performed at a physical layer where the type of transformation, such as manufacturing, transportation or distribution are handled by SCM. The physical layer does, however, rest on a generic process foundation represented by a logical layer based on generic transformations. This generic layer is the foundation for process management and consist of four decision categories [START_REF] Wikner | On decoupling points and decoupling zones[END_REF] that can be used at the logical layer and this is the foundation below. First a short summary of the logical layer is provided based on process management. Thereafter eight SCM strategies are outlined and finally the SCM strategies are interpreted in terms of the generic decoupling framework.

Process management decoupling framework

Process management as used here refers to a generic approach to managing flow based on some fundamental and generic decision categories. Four flow based decision categories are used below based on [START_REF] Wikner | On decoupling points and decoupling zones[END_REF]:

1. Flow driving involving the separation of speculation from commitment to customer order through the customer order decoupling point (CODP) and the customer order decoupling zone (CODZ). 2. Flow differentiation related to the uniqueness of the product ranging from standard, market unique, product to customer order unique special product which are separated by the customer adaptation decoupling point (CADP) and the customer adaptation decoupling zone (CADZ). 3. Flow delimitation concerns the reach of controllability. The flow can be separated into logical entities and the separation interface is related to the purchase order decoupling point (PODP) and the purchase order decoupling zone (PODZ). 4. Flow transparency is the fourth category and covers the availability of information where the demand information decoupling point (DIDP) limits the extension of demand information and the supply information decoupling point (SIDP) limits the extension of supply information.

These four categories are illustrated in Fig. 1 in combination with the strategic lead times that are critical for positioning these decoupling points and decoupling zones.

Supply chain management strategies

The physical perspective is related to the physical transformation performed in the supply chain. The intention here is not to give a comprehensive and all-encompassing view of a set of SCM strategies but rather to outline some insights on key properties in preparation for the discussion about how they can be interpreted in terms of the generic process management layer.

I. Segmentation:

Segmentation is related to that the supply chain should be designed to fulfil specific customer requirements [START_REF] Sharma | Segmentation of markets based on customer service[END_REF], which may require that separate supply chains are designed for different markets. This has been an important part of supply chain design since the early days of materials management and this field of research has evolved over time to segmented supply chain design [START_REF] Van Der Veeken | Logistics service management: Opportunities for differentiation[END_REF] II. Leagility: Whereas segmentation mainly targets the customer service aspect of SCM a separate stream of research has put more emphasize on the properties of supply. Leagility is focusing on the fundamental issue of how to combine lean, with emphasis on heijunka and levelled flow with agile, with emphasis on flexibility and speed. The combination has been referred to as "leagility" [START_REF] Mason-Jones | Engineering the leagile supply chain[END_REF][START_REF] Naylor | Leagility: Integrating the lean and agile manufacturing paradigms in the total supply chain[END_REF]. Leagility in this context basically represents how to balance efficiency with responsiveness.

III. Customization:

Leagility is a concept that decouples the supply chain but does not include any explicit consideration of customization, i.e. to which extent the product is made unique for a specific customer. Lampel and Mintzberg [START_REF] Lampel | Customizing Customization[END_REF] provided a comprehensive framework for categorization of customization. Note that this strategy encompasses a wide range of customization related strategies ranging from mass-customization [START_REF] Davis | Future perfect[END_REF] to engineer-to-order [START_REF] Hicks | Supply chain management: A strategic issue in engineer to order manufacturing[END_REF].

IV. Postponement:

In parallel to segmentation, leagility, and customization a separate stream of research has progressed and is referred to as postponement where decisions are postponed to as late as possible for better decision support. In the literature, postponement dates back to the 1950's when the concept was introduced [START_REF] Alderson | Marketing Efficiency and the Principle of Postponement[END_REF]. The concept of postponement was then developed further [START_REF] Bucklin | Postponement, speculation and the structure of distribution channels[END_REF] in terms of time, form, and place. Pagh and Cooper [START_REF] Pagh | Supply chain postponement and speculation strategies: How to choose the right strategy[END_REF] outlined a framework emphasizing speculation and postponement in terms of manufacturing as well as distribution to identify a set of strategies.

V. Servitization:

The four strategies outlined above all originates in the context of physical goods. Goods only has turned out to be a difficult strategy for many companies with limited access to low-cost manufacturing. An alternative strategy is to deliver a package of goods and services to the customers [START_REF] Wise | Go Downstream: The New Profit Imperative in Manufacturing[END_REF]. This approach has also been termed servitization [START_REF] Vandermerwe | Servitization of business: Adding value by adding services[END_REF] and is a subset of the more general concept of services.

VI. Sustainability:

By including services in the SCM strategy it is possible to take a more comprehensive approach to supply chains and to involve the whole life cycle of a product. SCM strategies are generally based on the forward supply chain but also a closed-loop perspective has emerged involving reverse flows. This topic originates in recycling which has evolved into product recovery management and the integrated supply chain [START_REF] Thierry | Strategic issues in product recovery management[END_REF]. This is also referred to as the closed-loop supply chain [START_REF] Daniel | Closed-loop Supply Chains, in Quantitative Approaches to Distribution Logistics and Supply Chain Management[END_REF] which encompasses both forward flows and reverse flows and in addition is closely related to the topic of sustainability [START_REF] Linton | Sustainable supply chains: An introduction[END_REF].

VII. Outsourcing:

Considering the resources performing the processes in the supply chain it is relevant to make a strategic choice related to the ownership of the resources. Originally the logical choice was to obtain vertical integration [START_REF] Ford | Today and tomorrow[END_REF] to obtain control but in many cases this is not possible, nor desirable. Instead the emphasis on core competence [START_REF] Prahalad | The core competence of the corporation[END_REF] grew stronger and as a consequence the intent was to outsource activities not considered as based on the core competence of the business [START_REF] Bettis | Outsourcing and Industrial Decline[END_REF]. This approach creates a better focus in each individual business but also contributes to the overall complexity of the supply chain as more actors are involved in the supply network.

VIII. Visibility:

Competitive SCM requires access to information about the actual state of the supply chain. The information basically concerns information about demand that creates requirement for resources and information about supply and the available resources. In the SCM context the main focus has been on demand information where demand visibility has turned out as an important factor for e.g. mitigation of the bull-whip effect [START_REF] Forrester | Industrial dynamics: a major breakthrough for decision makers[END_REF]. Visibility for resource capacity, i.e. supply, has evolved over time from simple sharing of information to a strategic element [START_REF] Lamming | Transparency in supply relationships: Concept and practice[END_REF] where visibility across several dimensions can be important [START_REF] Hultman | Towards a typology of transparency for marketing management research[END_REF].

4

Supply chain management strategies interpreted in terms of the process management decoupling framework

The eight SCM strategies outlined above have been associated with decoupling related aspects by different researchers and below follows a summary of this work. Fig. 1 illustrates the connection between the physical perspective represented by the SCM strategies and the logical perspective represented by the decoupling framework based on [START_REF] Wikner | On decoupling points and decoupling zones[END_REF]. Each strategy is expressed in terms of "level of" since the decoupling framework is based on positioning of decoupling points and decoupling zones across a leadtime based scale.

I. Level of segmentation:

The explicit connection to market segments was emphasized by Hoekstra and Romme [23 p. 65] when they introduced the concept of "product-market combination". They also introduced the concept of decoupling points for designing integral logistics structures and consequently they early realized the critical link between segmentation and decoupling points. Thereafter segmentation using decoupling points have emerged as a separate path of research, see e.g. [START_REF] Hilletofth | How to develop a differentiated supply chain strategy[END_REF]. In particular the aspect of flow driver (related to CODP and CODZ) is emphasized but implicitly this is also closely connected to how to create offerings that are adapted to specific market requirements and hence there is also a strong dependence on flow differentiation (related to CADP and CADZ).

II. Level of leagility:

Leagility was coined by Naylor, Naim [START_REF] Naylor | Leagility: Integrating the lean and agile manufacturing paradigms in the total supply chain[END_REF] and was basically defined using the CODP as a point of reference. Over time this idea has been further developed but still it is mainly the flow driver that is used as a point of reference (related to CODP and CODZ). The CODP has been emphasized by different authors in both lean and agile.

III. Level of customization:

Customization involves making a product unique for a particular market or even an individual customer. The topic of customization is broad but in particular two distinct approaches can be identified. First, it has been suggested that the flow driver should be considered from both a production perspective and an engineering perspective [START_REF] Wikner | Integrating production and engineering perspectives on the customer order decoupling point[END_REF], which has also been interpreted from a mass customization perspective [START_REF] Rudberg | Mass customization in terms of the customer order decoupling point[END_REF]. Second, the issue of customization and uniqueness provides additional complexity when the perspectives of customer and supplier are treated separately [START_REF] Wikner | Decoupling points and product uniqueness impact on supplier relations[END_REF]. Hence customization is mainly concerned with flow differentiation (related to CADP and CADZ)

IV. Level of postponement:

Postponement is a successful model for reduced risk exposure in both production and distribution. Central distribution and postponed product differentiation enables critical decisions to be postponed and to a larger extent become customer order driven. This provides an obvious connection to the flow driver (related to CODP and CODZ) as pointed out by e.g. [START_REF] Towill | Decoupling for supply chain competitiveness[END_REF]. Postponement is however also related to flow differentiation (related to CADP and CADZ) which is explicitly stated in [START_REF] García-Dastugue | Interorganizational time-based postponement in the supply chain[END_REF] as point of product differentiation and by [START_REF] Wikner | Postponement based on the positioning of the differentiation and decoupling points[END_REF] as differentiation point.

V. Level of servitization:

The level of servitization was, until relatively recently, not interpreted in terms of decoupling points. This is however appropriate when considering that there are many similarities between customer-order-driven activities and services. This analogy was first noted by Fließ and Kleinaltenkamp [START_REF] Fließ | Blueprinting the service company: Managing service processes efficiently[END_REF] and later further developed by [START_REF] Moeller | Customer Integration-A Key to an Implementation Perspective of Service Provision[END_REF] and [START_REF] Wikner | A service decoupling point framework for logistics, manufacturing, and service operations[END_REF]. In both these cases the emphasis were on flow drivers (related to CODP and CODZ) but obviously a fundamental aspect of services is the uniqueness of the offering and that it is differentiated for the customer (related to CADP and CADZ).

VI. Level sustainability:

Recycling, reverse flows, product returns, and closed loop supply chains are all terminology related to sustainable supply chains. To a large extent the theory development for this field has been separate from theory for forward flow supply chains. Reverse flows are usually more prone to stochastic events and consequently of much more uncertain character. Blackburn, Guide [START_REF] Blackburn | Reverse supply chains for commercial returns[END_REF] did however highlight that many concepts used in forward flow supply chains have a great potential also for reverse flows. One area they mentioned was postponement and [START_REF] Wikner | A structural framework for closed-loop supply chains[END_REF] developed this line of thinking in terms of decoupling points and in particular the flow driver was considered (related to CODP and CODZ).

VII. Level of outsourcing:

The first inclusion of purchased material into a decoupling point framework was by Hoekstra and Romme [START_REF] Hoekstra | Integral logistic structures : developing customer-oriented goods flow[END_REF] when they identified Purchase and make to order (PMTO) as a separate product-market combination. In this sense they considered purchasing as something taking place before production activities and hence included this in flow driving (related to CODP and CODZ). An alternative was developed by [START_REF] Mello | A framework to integrate engineering, procurement, and production on the customer order decoupling point[END_REF] that used two-dimensional CODP with production and engineering dimension and extended this approach to also include purchasing as a separate dimension making it into a three dimensional flow driver. An additional approach was suggested by [START_REF] Wikner | Aligning operations strategy and purchasing strategy[END_REF] that instead focused on if resources are within or outside the scope of control. In this sense they combined the flow driver with flow delimitation (related to PODP and PODZ) to more explicitly capture the controllability of the flow. In this context different scenarios of customer-supplier interaction can be defined by combining flow driving and flow delimitation.

VIII. Level of visibility in demand and supply:

Visibility is a supply chain strategy with a slightly different approach compared to the above. Instead of focusing on the decision maker and how to use information when making a decisions, visibility is focused on the availability of information for the decision maker. For demand visibilityMason-Jones and Towill [START_REF] Mason-Jones | Using the information decoupling point to improve supply chain performance[END_REF] introduced the concept of information decoupling point. Since different types of information are involved in visibility this is here referred to as demand information decoupling point (DIDP). Supply visibility has not received the corresponding interest from a decoupling perspective since availability of this kind of information is usually assumed. A corresponding decoupling point for supply information was suggested by [START_REF] Wikner | On decoupling points and decoupling zones[END_REF] and is referred to as supply information decoupling point (SIDP). This short overview of how the eight SCM strategies can be interpreted in terms of decoupling points and decoupling zones has highlighted some key similarities between the SCM strategies and also illustrated that the decoupling framework represent some fundamental aspects of SCM. It is, however, important to note that even if the analogy identifies some fundamental similarities between the different SCM strategies there are still many other aspects of the SCM strategies that are not covered here.

Fig. 1 .

 1 Fig. 1. SCM strategies and the decoupling framework

AcknowledgementThis research has been performed in collaboration with six companies in the projects KOPeration and KOPtimera. The projects are funded by the Swedish Knowledge foundation (KKS), Jönköping University and the participating companies.


Geraldo Cardoso De Oliveira Neto
email: geraldo.prod@ig.com.br

André Henriques Librantz

Washington Carvalho De Sousa

{geraldo Cardoso

Oliveira Neto

Logistic operator selection with capacity of storage and transport frozen product using multicriteria decision

Keywords: Selection, Logistic Operator, Multicriteria decision, Analytic Hierarchy Process

The aim of this work consisted in applying the Analytic Hierarchy Process (AHP) by considering the generic criteria and subcriteria to select logistic operator to store and transport frozen products. The outcome of the AHP analysis is a preference priority for each alternative operator describing the expected performance level. Results pointed that the proposed model could be considered as a good alternative to this problem, thus contributing to achieve the goals of the organization.

Introduction

The analytic hierarchy process (AHP) is a structured technique for organizing and analyzing complex decisions, The AHP method was developed during the 70's by Thomas Saaty [START_REF] Saaty | Decision Making with the Analytic Hierarchy Process[END_REF] to solve complex problems that involves multicriteria decisions [START_REF] Almeida | O conhecimento e o uso de métodos multicritério de apoio à decisão[END_REF] and has been extensively studied and refined since then. The applications of AHP to complex decision situations have produced extensive results in problems involving planning, resource allocation, priority setting, and selection of logistic operators, among alternatives.

AHP's use for logistic operator selection consists in an important aspect to identify and consider the criteria [START_REF] Iãnez | Uma metodologia para a seleção de um provedor de serviços logísticos[END_REF][START_REF] Kasture | FAHP Sensity Analysis for selection of Third party Logistics (3PL) service providers[END_REF][START_REF] Chen | Selection process in logistics managementa view from third party logistics provider[END_REF][START_REF] Asuquo | Modeling selection of third party ship management services. Case Studies on Transport Policy[END_REF], by knowing the contractor demands in order to achieve the main goal [START_REF] Daim | Use of analytic hierarchy process (AHP) for selection of 3PL providers[END_REF][START_REF] Reis | Contribution of the analytic hierarchy Process (AHP) method for supporting the decision to outsource or internalize activities in the context of technology-based company[END_REF], and evaluate alternatives and contract logistic operators that are more efficient [START_REF] Ho | Strategic logistics outsourcing: An integrated QFD and Fuzzy AHP approach[END_REF] adding value to the supply chain [START_REF] Routroy | Selection of Third Party Logistics Provider in Supply Chain[END_REF], by using a evaluation method of analysis before the contractual formalization [START_REF] Rajesh | Development of a composite model for selection of third party logistics service provider[END_REF][START_REF] Bansal | 3PL selection using hybrid model of AHP-PROMETHEE[END_REF][START_REF] Bayazit | Selection of a third party logistics service provider for an aerospace company: an analytical decision aiding approach[END_REF], to verify whether it is worth to outsource or internalize the activities [START_REF] Reis | Contribution of the analytic hierarchy Process (AHP) method for supporting the decision to outsource or internalize activities in the context of technology-based company[END_REF].

Usually the focus is on selecting a service provider that has the relational capacity to facilitate the business integration, operation and quality treatment [START_REF] Gol | Third-party logistics provider selection: insights from a Turkish automotive company[END_REF], that turns out more feasible to collaboration [START_REF] Sasikumar | A multi-criteria decision making methodology for the selection of reverse logistics operating modes[END_REF], including establishing common goals to control the performance and the strategic alignment of the partnership [START_REF] Xiu | The Third Party Logistics Supplier Selection and Evaluation[END_REF] to manage the service level [START_REF] Peng | Selection of Logistics Outsourcing Service Suppliers Based on AHP[END_REF].

Regarding the quality analysis, it was developed a model based on SERVQUAL (quality dimensions), taking into account the criteria utilized for logistic operator selection [START_REF] So | Evaluating the service quality of third party logistics service providers using the analytic hierarchy process[END_REF].

It has been found some works, in which the AHP method was used to select logistic service providers to operate reverse logistic that could be considered a complex decision, once it is a recent operation, that needs reliability [START_REF] Senthil | A decision making methodology for the selection of reverse logistics operating channels[END_REF][START_REF] Senthil | A robust hybrid multi-criteria decision making methodology for contractor evaluation and selection in third-party reverse logistics[END_REF][START_REF] Chiang | A third party logistics provider for the best selection in Fuzzy dynamic decision environments[END_REF][START_REF] Bhatti | Analytical Modeling of third party service provider selection in lead logistics provider environments[END_REF], with contractual renegotiation guaranteed politics [START_REF] Bhatti | Analytical Modeling of third party service provider selection in lead logistics provider environments[END_REF] and mainly, really contributes with sustainability by reducing waste on transport and storage [START_REF] Sasikumar | A multi-criteria decision making methodology for the selection of reverse logistics operating modes[END_REF]. Other researchers used the AHP to select logistic operators to act on manufacturing of contractor [START_REF] Rosa | Avaliação multicriterial de desempenho e separação em aglomerados de fornecedores críticos de uma manufatura OKP[END_REF][START_REF] Grewal | A multicriteria logistics-outsourcing decision making using the analytic hierarchy process[END_REF].

In Table 1 it is shown the logistic operator selection generic criteria and subcriteria developed by action research in logistic services outsourcing processes on Brazil in the last six years. But, with a deep revision in literature it was possible to identify the researches that corroborate with the criteria and sub-criteria established on practice, making it possible to assure that it is made of a 15 criteria and 67 subcriteria basis consolidated on theoretical research field.

In the literature review it wasn't identified researches that utilize the AHP to select logistic operators that storage and transport frozen refrigerated products and it was noted that it misses a more complete criteria and sub-criteria basis to apply the multicriteria analysis in outsourcing processes. Some researches produced fragmented results [START_REF] Iãnez | Uma metodologia para a seleção de um provedor de serviços logísticos[END_REF][START_REF] Reis | Contribution of the analytic hierarchy Process (AHP) method for supporting the decision to outsource or internalize activities in the context of technology-based company[END_REF][START_REF] Ho | Strategic logistics outsourcing: An integrated QFD and Fuzzy AHP approach[END_REF][START_REF] Gol | Third-party logistics provider selection: insights from a Turkish automotive company[END_REF][START_REF] So | Evaluating the service quality of third party logistics service providers using the analytic hierarchy process[END_REF][START_REF] Bhatti | Analytical Modeling of third party service provider selection in lead logistics provider environments[END_REF] that makes it impossible to make decision.

In this context, the aim of this work consists in applying the AHP with support of the generic criteria and sub-criteria basis of logistic operator selection of storage and transport of frozen products.

Methodology

At first, the literature revision [START_REF] Cooper | Research synthesis and meta-analysis[END_REF] was performed in the following data bases: Proquest, Ebsco, Science Direct, Emerald, Capes and academic Google, with the following keywords: (i)"Analytic hierarchy process" AND "outsourcing" AND "logistics"; (ii) "Analytic hierarchy process" AND "selection" AND "third party logistics"; (iii) "Analytic hierarchy process" AND "selection" AND "third-party logistics" e (iv) "Analytic hierarchy process" AND "selection" AND "service provider" with the objective of electing the articles that utilized the AHP to select the logistic operators, summarizing 24 researches, that were submitted to content analysis to categorize the data in a spread sheet [START_REF] Bardin | El análisis de contenido[END_REF] of the main themes and criteria utilized.

The utilized method was action research, in which the researcher is involved, along with the members of the analyzed organization, to deal with a problem, specifically in the appropriate selection of a logistic operator of storage and transport of frozen load [START_REF] Bryman | Research Methods and Organization studies[END_REF], with that, the researcher participates in the process [START_REF] Westbrook | Action Research: a new paradigm for research in production and operations management[END_REF][START_REF] Coughlan | Action research for operations management[END_REF][START_REF] Thiollent | Metodologia da pesquisa-ação. 15ºed[END_REF].

The process of action research involves five stages [START_REF] Westbrook | Action Research: a new paradigm for research in production and operations management[END_REF][START_REF] Coughlan | Action research for operations management[END_REF][START_REF] Thiollent | Metodologia da pesquisa-ação. 15ºed[END_REF]: (i) Action research planning:in this step, it was identified along with the contractor, the insecurity in selecting a logistic operator to move and transport frozen products, which brought up the following research's question: how to select a logistic operator appropriate to store and transport frozen products.

(ii) Instruments to collect field data:active participation in meetings, focal groups and documents analysis. The focal groups or observation groups generate important lessons about the observed phenomenon [START_REF] Thiollent | Metodologia da pesquisa-ação. 15ºed[END_REF].

(iii) Action Plans: -the decision making relative to logistic operator selection inevitably includes a consideration and evidence based in multiccriteria for the decision making [START_REF] Iãnez | Uma metodologia para a seleção de um provedor de serviços logísticos[END_REF][START_REF] Kasture | FAHP Sensity Analysis for selection of Third party Logistics (3PL) service providers[END_REF][START_REF] Chen | Selection process in logistics managementa view from third party logistics provider[END_REF][START_REF] Almeida | O conhecimento e o uso de métodos multicritério de apoio à decisão[END_REF][START_REF] Asuquo | Modeling selection of third party ship management services. Case Studies on Transport Policy[END_REF]. With that in mind, we adopted 16 criteria and 67 sub-criteria of logistic operator selection [START_REF] Oliveira | Estratégia em Terceirização para contratação de Operador Logístico: uma abordagem teórica sob a ótica da teoria baseada em recursos[END_REF].

Empathy

After-Sell and Commitment [START_REF] So | Evaluating the service quality of third party logistics service providers using the analytic hierarchy process[END_REF][START_REF] Gol | Third-party logistics provider selection: insights from a Turkish automotive company[END_REF].

Environmental Certification ISO 14000; Cleaner Production; Reverse Logistic and Training in environmental education [START_REF] Iãnez | Uma metodologia para a seleção de um provedor de serviços logísticos[END_REF][START_REF] Bhatti | Analytical Modeling of third party service provider selection in lead logistics provider environments[END_REF][START_REF] Sasikumar | A multi-criteria decision making methodology for the selection of reverse logistics operating modes[END_REF][START_REF] Xiu | The Third Party Logistics Supplier Selection and Evaluation[END_REF][START_REF] Senthil | A decision making methodology for the selection of reverse logistics operating channels[END_REF][START_REF] Senthil | A robust hybrid multi-criteria decision making methodology for contractor evaluation and selection in third-party reverse logistics[END_REF] Source: [START_REF] Oliveira | Estratégia em Terceirização para contratação de Operador Logístico: uma abordagem teórica sob a ótica da teoria baseada em recursos[END_REF][START_REF] Oliveira | Integração complexa entre empresa contratante e operador logístico: Critérios para contratação[END_REF] corroborated with some researches In fact the process of decision making is commonly complex. The multiccriteria Decision Analysis could support the decision maker to solve problems in which there are many goals to be reached at the same time. Three sets are initially considered in the formulation of multiccriteria decision problems: the set of alternatives, the set of criteria and the set of consequences [START_REF] Deng | A new fuzzy dempster MCDM method and its application in supplier selection[END_REF]. The process consists of the following stages: (1) Define the alternatives; (2) Define the relevant criteria to the decision problem; (3) Evaluate the alternatives related to the criteria; (4) Evaluate the relative importance of each criteria and (5) Determine the global evaluation of each alternative.

Along the methods developed in the Multiccriteria Decisions research, the most well-known is the Analytic Hierarchy Process -AHP, developed by Thomas Saaty [START_REF] Saaty | Decision Making with the Analytic Hierarchy Process[END_REF] to identify the relevant criteria through binary correlation, which allows to associate a priority value above other elements in a numerical scale, merging an hierarchical structure of the problem of decision with support of the mathematical modeling.

As an example, when using the decision matrix A, the AHP method calculates the partial results of the A set inside each criteria vi(Aj), j = 1, …, n, called impact value of the j alternative in relation to the i alternative, in which these results represent numerical values of the given data by the decision maker in each alternative comparison. The results are standardized by the expression 1:

Σ i =1 v i (A j ) = 1, for j = 1, ..., n;

(1) where n is the number of alternatives or compared elements. Each part of the sum consists in: v i (A j ) = a ij / Σ i =1 a ij , for j = 1, ..., n.

This expression relates the priority vector of the alternative i in relation to the C k criteria be: v k (A i ) = Σ j =1 vi(A j ) / n , for i = 1, ..., n After having the priority vector or the impact value of the alternatives under each C k criteria, the next step is the criteria levels. In this case, we adopt again the verbal scale to the classification pair-to-pair of the criteria, that are standardized by the expression 2:

wi(C j ) = C ij / Σ i =1 C ij , for j = 1, ..., m;

(2) where m is the number of criteria in the same level. The priority vector is obtained by: w i (C i ) = Σi=1 w(Cj) / m , for i = 1, ..., m;

(3) Finally, the final values of the alternatives are obtained through an aggregation process, standardized by the expression 4, in which: f(A j ) = Σi=1 w(C i ) * v i (A ) , for j = 1, ..., n; (4) where n is the number of alternatives (iv) Implanting Actionsscale selection for decision making to identify the most relevant contractual criteria. The Table 2 shows the scale.

Tabela 2. Criteria Evaluation Scale

Value

Definiton Explanation 1 Same Importance Both criteria contribute in the same way to the objective. [START_REF] Iãnez | Uma metodologia para a seleção de um provedor de serviços logísticos[END_REF] Little more Important The analysis and experience prove that a criteria is a little more important than the other. 5

Much more Important The analysis and experience prove that a criteria is much more important than the other. 7

A lot more Important The analysis and experience prove that a criteria is a lot more important than the other. 9

Hugely more Important Without doubt, a criteria is predominant over the other one.

Source: based on Saaty [START_REF] Saaty | Decision Making with the Analytic Hierarchy Process[END_REF].

Logistic Operator Selection with storage and frozen product transport capacities using multicriteria decision5

(v) Discuss Resultsthe final stage implies in learning through reflection among the results of the action of the participants [START_REF] Coughlan | Action research for operations management[END_REF] to verify which logistic operator can successfully fulfill the operational capacities (criteria) required as described in the following stage.

Results and Discussion

The main focus of the corporation is the product industrialization. Thus, they decided to outsource its storage and frozen product transport processes, taking into account the dispatching capacity of the operators. So, three logistic operators have been chosen to be analysed by AHP method.

Numerical Application

In this section, the multi-criteria group decision model is applied to a procedure for selecting logistic operators. In order to obtain the Multicriteria numerical application it was used the AHP method based on the 16 criteria and 67 sub-criteria, allowing an identification of seven more critical criteria. The main criterion to be observed in the logistic operators' evaluation is the transport responsiveness. However, to make the responsiveness capacity better to the market, it was required criteria of infrastructure (physical resources) to improve the storage capacity, that was missing physical space in the appropriate floor to allocate 134 tons a day -4 freezing tunnels that allocate 26 docks and infrastructure criteria (physical resources) to improve the transport capacitystrategic localization near the beltway to deliver the products quickly.

This way, the main concern of the contractor was the complementation of storage and transport capacities, variables associated to the responsiveness and infrastructure criteria. It is important to note that the contractor was not only worried about analyzing the physical resources to store and transport, as well, but the managing capacity of the logistic operator within these activities, by considering the efficiency indicators implantation required integrated with fee applications in case of non-effectiveness.

The results pointed that the qualitative analysis should precede the AHP application with the objective of knowing the demands of the contractor regarding the capacities. In most published works, decision makers applied the multicriteria analysis [3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 21, and 32], neglecting the qualitative evaluation. Many authors pointed out the need of relational capacity without a deeper analysis of the other required capacities [14, 15, 17, and 28]. The relational capacity and the quality capacity can be considered generic, because this is a common necessity in any outsourcing process, being required a deeper analysis on the operational routine of the contractor to identify specific capacities, as shown in the results.

Table 3 shows the consequence matrix with critic criteria obtained after the model application. The numbers were normalized to obtain the relative importance (pair-wise comparison). Based on the seven critical criteria, the three logistic operators were analyzed. Once obtained the decision matrix, it was possible to evaluate the score and classify the logistic operators, indicating which of them was considered more able to store and transport frozen products.

The logistic operator 2 (score 0.41) was considered more able to improve the dispatch responsiveness of the contractor in the metropolitan region of São Paulo, because it is in a strategic localization near the beltway, allowing better product outflowing, among having better consolidated infrastructure concerning equipment, as for an example, term kings to control the temperature, and freezing tunnels in the warehouse.

The second-best (score 0.23) was the logistic operator 1 that presented low capacity of infrastructure that could prejudice the dispatching responsiveness.

Finally, the logistic operator 3 (score 0.21), that presented lack of control in the efficiency of the provided services, making it impossible to analyze the punctuality indicators of dispatch.

Both logistic operators 1 and 3 were not localized near a beltway, which was considered, by the contractor, a crucial aspect.

This results corroborate with the researches of [START_REF] Senthil | A decision making methodology for the selection of reverse logistics operating channels[END_REF][START_REF] Senthil | A robust hybrid multi-criteria decision making methodology for contractor evaluation and selection in third-party reverse logistics[END_REF] related to the development of a ranking to avoid the opportunist behavior of logistic operator regarding the possibility of offering sets of generic services that do not meet the contractor demands and could lead to the outsourcing failure.

Conclusions

In this work, the AHP technique was used in the selection of logistic operators to store and transport frozen products. The AHP is a structured technique for organizing and analyzing complex decisions, and coub be useful, especially in complex decision processes, once it enables people to make decisions involving many kinds of concerns including planning, setting priorities, selecting the best among a number of alternatives, and allocating resources. Complex problems or issues involving value or subjective judgments are suitable applications of the AHP method. Its approach of division in hierarchical criteria and alternative correlation with criteria, allows an easy comprehension and better evaluation of the problem. Taking into account that many strategic decisions, such as logistic operator selection, are many times, made without any methodical support, the proposed model can be considered as a good alternative to the investigated problem, since it can support the decision process, which can contribute to increase efficiency of the supply chain of the organization.

Table 1 .

 1 Criteria and Sub-criteria of logistic operator selection.

	Criteria	Sub-criteria	Corroborating Researches
	Cost	Transport; Storage and handling; Delay on supplying and Devolutions.
	Operation Management	Management of: people; loading; receipt; storage; transport; quality and information.	[14, 22, 19]
	Flexibility	Treatment capacity; Negotiated nuances and Treatment Service to the	[23, 3, 21, 15, 9,
		Clients.	19, 8]
	Credibility	Business Reputation; Logistic Partnership and amount of Contracts per year.	[3, 14, 22, 6]
	Experience	Service efficiency; Product's amount of experience; Amount of time in	[14, 7, 20, 6]
		the market and Clients range.
	Quality	Quality Certification; Physical Integrity Compatibility; Logistic	[23, 14, 21, 22, 9,
		Operator seeks improvement in the process and Traceability.	8
	Information	Easy Communication (Electronic Data Interchange -EDI); (Enterprise
	Technology	Resource Planning -ERP); (Warehousing Management System-WMS); (Transport Management System TMS) and Routing (Global Positioning	[23, 9, 19, 17, 20]
		System -GPS).
	Human Resources	Employees Qualification; Capacity of Working in Group; Capacitation and practical test, Clothing and neatness of the employees.	[14, 21, 22]
	Reliability	Complete Order Dispatching; Classified Information Leaking; Security against load stealing and Fines due to no-treatment.	[18, 8]
	Responsibility Operation in JIT and Dispatch in short term.	[18, 23, 21, 22, 15, 16, 17, 8]

[START_REF] Rosa | Avaliação multicriterial de desempenho e separação em aglomerados de fornecedores críticos de uma manufatura OKP[END_REF][START_REF] Chiang | A third party logistics provider for the best selection in Fuzzy dynamic decision environments[END_REF][START_REF] Daim | Use of analytic hierarchy process (AHP) for selection of 3PL providers[END_REF][START_REF] Peng | Selection of Logistics Outsourcing Service Suppliers Based on AHP[END_REF][START_REF] Ho | Strategic logistics outsourcing: An integrated QFD and Fuzzy AHP approach[END_REF][START_REF] Reis | Contribution of the analytic hierarchy Process (AHP) method for supporting the decision to outsource or internalize activities in the context of technology-based company[END_REF]

Financial stability

Investment Capacity; Financial Health and Indebtedness. [3, 14, 22, 9, 8] Adaptability Logistic Operator in lócus with the Contractor; Flexibility in the treatment, Cultural Compatibility and Common Planning. [17, 8] Operation Infrastructure Distribution Centers Location; Facilities Adequacy; Work Security; Loading; Truck Conditions; Equipment required for loading; Receipt in JIT without fault in the Logistic Operator; Equipment required in receipt; Equipment required for Moving; Handling Pallets without fault; Storage and Stacking in the warehouse; Equipment required in the warehouse; Separation to dispatch without fault; Uniting and Own cars;

Equipment required to transport and dispatch of the order without fault in JIT.

[START_REF] So | Evaluating the service quality of third party logistics service providers using the analytic hierarchy process[END_REF][START_REF] Iãnez | Uma metodologia para a seleção de um provedor de serviços logísticos[END_REF][START_REF] Bhatti | Analytical Modeling of third party service provider selection in lead logistics provider environments[END_REF][START_REF] Xiu | The Third Party Logistics Supplier Selection and Evaluation[END_REF][START_REF] Peng | Selection of Logistics Outsourcing Service Suppliers Based on AHP[END_REF][START_REF] Reis | Contribution of the analytic hierarchy Process (AHP) method for supporting the decision to outsource or internalize activities in the context of technology-based company[END_REF][START_REF] Senthil | A robust hybrid multi-criteria decision making methodology for contractor evaluation and selection in third-party reverse logistics[END_REF][START_REF] Asuquo | Modeling selection of third party ship management services. Case Studies on Transport Policy[END_REF]

Table 3 .

 3 Consequence Matrix.

	Criteria	Operation Infrastructure	Operation Management	Quality	Tech-nology	Human Resources	Relia-bility	Respon-siveness
	Operation Infrastructure	1,000	1,000	0,111	0,111	0,111	0,111	0,111
	Operation Management	1,000	1,000	0,111	0,111	0,111	0,111	0,111
	Quality	3,000	1,000	3,000	0,333	0,333	0,333	0,333
	Technology	3,000	1,000	0,600	0,333	0,333	0,333	0,333
	Human Resources	3,000	1,000	0,600	0,333	0,333	0,333	0,333
	Reliability	3,000	1,000	0,600	0,333	0,333	0,333	0,333
	Responsiveness	9,000	1,000	1,800	1,000	1,000	1,000	1,000

Table 4 .

 4 Table 4 presented the decision matrix and the results obtained for each alternative. Decision Matrix

	Alter-native	Operation Infrastructure	Operation Management	Quality	Tech-nology	Human Resources	Relia-bility	Respon-siviness
	LO 1	0,195	0,210	0,397	0,162	0,302	0,250	0,203
	LO 2	0,520	0,519	0,503	0,543	0,397	0,491	0,593
	LO 3	0,284	0,271	0,101	0,295	0,302	0,259	0,203


Ralph Riedel
email: ralph.riedel@mb.tu-chemnitz.de

Ulrike Starker
email: ulrike.starker@uni-bamberg.de

Rüdiger Von Der Weth

A Multidisciplinary Model of Problem Solving in Complex Production Systems

Keywords: production system, modelling, simulation, problem solving

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Industrial companies, and therefore production and logistics systems, face new challenges such as an increasing level of globalization and networked production, a reduced and diversified workforce potential, shorter product lifecycles, etc. This leads to a changing role of humans in production systems -they need to continuously adapt to new situations, new technology, new processes and new organizations [START_REF] Rösio | Reconfigurable production system design -theoretical and practical challenges[END_REF]. Therefore, production systems need to be designed in a way that they facilitate learning processes and that they foster the motivation and competence of workers to cope with changes, deviations from normality and disturbances. Beside cognitive capabilities, emotional factors like anxiety or confidence also play a decisive role. As a consequence certain design strategies for work systems, working processes and for the whole production systems have to meet the aforementioned requirements. As a prerequisite a sound understanding of the basic psychological processes and their interactions with system's characteristics is absolutely necessary. Therefore, qualitatively improved models of production systems are needed to support the analysis and design of sophisticated solutions. In this paper we present a conceptual framework for such an integrated model by which it will be possible to map and to integrate the problem solving and learning capabilities of workers in production systems based on basic emotional factors and psychological mechanisms. This extended sociotechnical model will also be able to close a transaction gap between planning and reality.

The paper is organized as follows: First we will discuss briefly the state of the art of production system modelling. In a second part we will refer to the basics of problem solving and problem solving capability. In the main part of the paper we will explain our concept of a multidisciplinary, integrated model of production systems. After a short overview of the model's architecture we will unfold its single components. Finally we will draw some conclusions and we will give an outlook on future research, also addressing some hypotheses about the behavior of the extended model.

Modelling of production systems

The planning of production systems as well as operations management is usually based on a system modelling approach, i.e. the analysis, evaluation and design of such systems is done with the help of models [START_REF]VDI 5200: Factory planning -Planning procedures[END_REF]. Such models normally cover the elements of the system (like technical equipment, products and material, workers) and their interaction (material flow, processing time etc.). Often the models are used for simulations [START_REF]VDI 3633: Simulation of systems in materials handling, logistics and production[END_REF] where experiments are conducted to test for example different parameter settings. Simulation-ready models can be found in a multitude of applications in production systems planning, e.g. in supply chain management and for the optimization of logistics processes [START_REF] Chang | Supply Chain Modelling Using Simulation[END_REF], for transportation processes in micro-and macrologistics [START_REF] Dangelmaier | Using Dynamic Multiresolution Modeling to Analyze large Material Flow Systems[END_REF], for planning and scheduling problems [START_REF] Hildebrandt | Towards improved dispatching rules for complex shop floor scenarios: a genetic programming approach[END_REF], for the configuration of production networks and for ramp-up processes [START_REF] Weiler | Supply chain design for the global expansion of manufacturing capacity in emerging markets[END_REF][START_REF] Fleischer | A Dynamic Business-Process Based Production Rampup Simulation Model[END_REF], etc. Usually such models cover mainly technical aspects and mirror the modelled system at its normal operation mode. Although recent approaches of artificial intelligence [START_REF] Scholz-Reiter | A Concept for Simulation of Autonomous Logistic Processes[END_REF] make use of certain concepts of human information processing, the human itself as an autonomous subject and the dynamic interaction of such subjects has not yet been addressed. Also other sophisticated approaches like the person oriented simulation [START_REF]VDI 3633/6: Representation of human resources in simulation models[END_REF], the analysis of decision systems [START_REF] Zülch | Modelling and Simulation of Human Decision Making in Manufacturing Systems[END_REF], the integration of human performance models (circadian rhythm) in simulation tools [START_REF] Baines | Humans: the missing link in manufacturing simulation?[END_REF] or learning-capable and communicative agents in socio-cultural processes [START_REF] Sun | The CLARION cognitive architecture: Extending cognitive modeling to social simulation In[END_REF] have not been able to fill the gap.

It can be concluded that the demand for integrating human behavior into production system's models has already been identified [START_REF] Baines | Humans: the missing link in manufacturing simulation?[END_REF] [START_REF] Grabot | A socio-technical view on Supply Chain Management problems[END_REF][START_REF] Riedel | Building Decision Systems for Acceptance[END_REF]. However, there are only a few concrete modelling approaches so far and even fewer approaches with a profound psychological background which can be used for predicting human behavior in such systems. Emotional regulation, complex problem solving processes and the interaction of several subjects haven't been included in production systems models so far.

Problem solving and problem solving competence

The main challenge in integrating human behavior in production systems emerge from modelling human behavior, which is able to solve the complex problems described above. The ability to solve complex problems refers to several demands. E.g. the most accurate test for cognitive sub-functions in complex problem solving is about "decision making", "system analysis" and "searching for mistakes" [START_REF] Leutner | Analytical and dynamical problem solving… In[END_REF]. Moreover it is basic knowledge in psychology that success in problem solving is not only based on cognitive abilities and skills. In critical situations coping with problems depends highly on the actual level of subjective control [START_REF] Selye | Stress and disease[END_REF][START_REF] Lazarus | Emotion and adaption[END_REF]. If problems are increasingly new, opaque and complex, the chance to derive plans and decisions from consolidated knowledge becomes more and more improbable and this itself is a stressor by reducing the level of control. Because of that typical mistakes were found in experiments simulating complex situations. These mistakes are far beyond the intellectual level of the actors and their probability is high [START_REF] Dörner | The logic of failure[END_REF]. Generally a lower performance occurs in decision making under stress [START_REF] Cannon-Bowers | Making decisions under stress: implications for individual and team training[END_REF]. However, empirical studies show that a general high level of self-efficacy improves the performance of problem solvers [START_REF] Dörner | The logic of failure[END_REF], [START_REF] Bandura | Self-efficacy: Toward a unifying theory of behavioral change[END_REF][START_REF] Jerusalem | Emotion, Motivation and Performance[END_REF]. Erpenbeck & Rosenstiel [START_REF]Handbook competence measurement: recognizing, understanding and evaluating competencies in organizations, pedagogy and psychology[END_REF] have the hypothesis that a high level of self-efficacy is also improving the tendency and ability to act autonomous in difficult situations. Self-efficacy in work situations is not a personal trait. It depends on learning in problem solving situations. In work context it depends on several aspects [START_REF] Der Weth | Integrating motivational and emotional factors in implementation strategies for new enterprise planning software[END_REF]:  knowhow in the specific domain  general problem solving experience  integration in well performing organizational processes  social support.

Studies by Starker [START_REF] Starker | Emotional Adaptivity[END_REF] show that successful entrepreneurs have the ability to develop strategies for emotion regulation in complex situations. Students who have the ability to change actively their mood in problem solving situations have significantly better results in a computer simulated management game.

The interaction of emotion and cognitive processes in problem solving behavior was also tested in cognitive science research about action regulation. Basing on the PSI-model of Dörner [START_REF] Dörner | Blueprint of a soul[END_REF] virtual agents have been programmed to develop strategies for survival in a fictitious micro-world [START_REF] Dörner | Should successful agents have emotions?[END_REF][START_REF] Elkady | Simulating different human Action Strategies in Uncertain Environments[END_REF]. Different types of computer programs (emotional vs. non-emotional) and real subjects have controlled the agents in the micro-world. Artificial agents with simulated emotional functions and real subjects were more similar and showed a different behavior compared to non-emotional programs. They were also more successful. The basic principles of the emotional agents of these studies were used for developing an emotional problem solver in our own work described now.

Multidisciplinary model of production systems 4.1 Architecture

To integrate human behavior in a dynamic model of the production system we have to understand the processes at three levels.

 Production model: The production system level describes the activities and interaction of machines and workers as a whole. Human behavior is the central resource for problem solving and therefore also for innovation, change and the management of dysfunctional processes. Human behavior is unique, that means two persons can behave differently in the same situation and one person will not repeat automatically the same behavior in the same situation. The production model describes, which forms of organization and processes fosters problem solving activities and which kind of human problem solving activities are improving performance and problem solving capability of the whole production system  Incentive model: On the work system level it is described how a specific work situation impacts a specific individual. Which part of the reality is experienced on a specific work place? Which incentives and affordances exist in this work situation and how do they differ depending on the knowledge and the emotional state of the specific person? How can the work place be improved to encourage and enable people to more problem solving activity?  Behavior model: The behavior model describes how the incentives influence the individual regulation of behavior and how this behavior influences the performances of the production system and changes it. The behavior model is dynamic. Actual control, self-efficacy, learning processes and problem solving strategies are changing in the process. This influences performance and the kind and intensity of problem solving activities.

The model shall allow insights which organizational structures, formal processes and work place designs encourage workers to solve problems autonomously and which are the prerequisites that these autonomous activities improve the problem solving capability of the whole production system.

Production model

The core of the extended production model covers the interaction between design parameters of the production system, the capability for problem solving and learning as well as central system indicators. The approach is presented in fig. 1.

Fig. 1. Extended model of production systems

The description of problem solving and learning processes are crucial for the extended production model. Those are dependent on parameters of the situation, the task itself as well as the person. Those problem solving and learning processes are triggered by external (or even internal) assignments. Hereby, unexpected events resulting from internal or external dynamics, for instance changes in the production program, technology changes, disturbances, etc., play an important role. The problem solving and learning processes themselves lead to certain results which have an impact on the processes and stages in the production system. The system, esp. its behavior, can then be evaluated by key indicators like robustness, resilience, adaptability, productivity etc.

As the influence of structural and process parameters on economic and logistics performance indicators is already well known, the innovative core of the extended production model lies in the impact of system's design parameters on indicators for the efficient and effective reaction on disturbances, deviations and changes -see fig. 2.

Fig. 2. Variables in the extended production model

The knowledge about those interdependencies will finally lead to a contingency model from which the suitability of certain system's configurations under given circumstances (characteristics of the situation, of the task, of the organization, of the persons) can be derived.

The extensions of the production model need to be linked to already existing modelling concepts for production and logistics like input-output-models, process chains, etc. The extensions are among others the availability and quality of information regarding deviations and disturbances, prognosis options, alternative activities and process structures, including alternative resource allocation, etc. as well as their impact on system's performance and adaptability. For specification and formalization such approaches like "what-if-then" rules, parametric models, characteristic curves could be applied.

Incentive model

The incentive model is based upon classical work Lewin [START_REF] Norman | The psychology of everyday things[END_REF], Gibson [START_REF] Lewin | Main Features of a topological Psychology[END_REF] and Norman [START_REF] Gibson | The Theory of Affordances[END_REF]. The input for this level is both the actual data of the production system and the actual state and position of the respective worker. Depending on the production data and his actual coordinates the actual perceptual field can be computed. The incentives for activities which are in this field depend on his knowledge (e.g. about the correct use of a certain tool) and his actual plans and mood. The authors are especially interested in incentives for autonomous problem solving activities. The amount of incentive varies from person to person, depending on knowledge, problem solving abilities and self-efficacy. On the other hand there exist organizational restrictions like the amount of time, which can be used for a problem solving activity, the formal rules for work in the production system for the handling of incidents and dysfunctions. Additional factors are the availability and motivation for colleagues´ support.

Behavior model

The behavior model describes the internal processes of action regulation and how the external incentives and the cognitive and emotional prerequisites of the specific workers are computed to a behavior program. The program is an adapted version of the general PSI-agent described before. It is changed for the specific purposes of the production-system-simulation. The most important internal variable is the actual level of subjective control and the possible changes which occur when a worker follows the respective incentives of the possible alternatives. The results of his activities depend on his knowledge and his actual mood. There are three kinds of results: a change in the production system, a development of his knowledge and maybe a change in the workers mood. For starting problem solving activities the person needs an acceptable internal level of self-efficacy, knowledge and appropriate problem solving strategies. All these factors increase the tendency for autonomous problem solving activity for the specific individual. This tendency becomes even stronger when the organizational framework supports social interaction and mutual help.

Conclusion and outlook

As discussed the proposed model should be able to allow better prognoses about autonomous problem solving behavior of workers in corresponding production processes in reality. The next important step will be to develop the validity and explanatory capability of the model. At the moment a real production system in a laboratory setting is planned which should serve as benchmark towards the prognoses of an also more sophisticated simulation model. A first simulation based upon the model produced plausible results about fictitious workers´ behavior in a production system [START_REF] Riedel | Integrating Human Behaviour into Factory Simulation -a Feasibility Study[END_REF] and proofed the feasibility of the approach. Planned experiments will lead to insights on how certain configurations of production systems and workers with specific prerequisites influence the readiness for problem solving activities. By comparing the prognoses of the model with real human behavior in the laboratory production system, the model will be improved step by step (so called corner stone method). The long term objective of the presented and continuing research work is a better understanding in which way the organization of production systems and the design of work places, processes and working conditions influence problem solving in production systems.


Mary Dempsey
email: mary.dempsey@nuigalway.ie

Ralph Riedel
email: ralph.riedel@mb.tu-chemnitz.de

Martina Kelly
email: martinakelly@nuigalway.ie

Serious Play as a Method for Process Design

Keywords: Lego Serious Play, new product development, process design, participative design processes

de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Due to current challenges from a dynamic and global economy enterprises are forced to maintain and improve competitiveness. This requirement for improvement is mainly based on effective and efficient processes as well as innovative products and services. The need for flexible and competitive processes encompasses not only production and logistics but also the necessary supportive and administrative processes. It also extends to early activities in the product lifecycle such as product development.

Well-established principles already exist for the efficient design of production and logistics processes, many of which have been developed within the Lean Management paradigm. With respect to supportive and administrative processes, business process re-engineering (BPR) and business process management (BPM) techniques are well supported. However, when faced with new product development and the product development lifecycle process, greater challenges exist. Due to the inherent complexity of process analysis and process design, enterprises tend to follow heuristic principles. These principles are based predominately on the knowledge of the people involved in the processes. Moreover, in every process and organizational design endeavor the people affected need to be involved not only for their specialist know-how but they must identify with and accept the solution in order to guarantee a successful outcome.

As motivating and including people is a crucial aspect in any change process there is always a need for methods and tools to support this. Serious Play approaches are one approach to not only unleashing people's creativity but also including them actively in the creative problem solving processes and thereby building identity with the developed solution. LEGO® SERIOUS PLAY ® (LSP) was developed to be an innovative, experiential process and has been shown to extend players' awareness of problems and ideas, and to enhance creativity and enable teamwork. This paper details the results of a case study which uses LSP as a tool to support the development of an effective New Product Development Life Cycle (NPDLC) process.

2

Theoretical background and methodology

Process reengineering and implementing change

Evaluating, rethinking and reengineering are increasingly seen as a way to improve the productivity, product quality and operations of a company [START_REF] Lee | Business process management: a review and evaluation[END_REF]. Hereby, it is widely agreed that the implementation phase of a newly designed process is of major concern [START_REF] Grover | The implementation of business process reengineering[END_REF]. Solving technological and project planning issues are necessary, but not sufficient, preconditions for the success of a process reengineering endeavor [START_REF] Grover | The implementation of business process reengineering[END_REF]. Reengineering processes, especially creative and collaborative processes like product development or production planning, are complex, involving numerous factors and especially people from different, heterogeneous backgrounds [START_REF] Grover | The implementation of business process reengineering[END_REF]. The literature suggests that the main factors in ensuring successful change are giving ownership to people, providing and communicating a clear vision, empowering people, and leadership [START_REF] Paton | Change Management[END_REF][START_REF] Fritzenschaft | Critical Success Factors of Change Management[END_REF][START_REF] Cameron | Making Sense of Change Management[END_REF][START_REF] Trkman | The critical success factors of business process management[END_REF].

Although there is wide agreement that empowering people, facilitating team work and (autonomous) team decisions are necessary in the decision-making process, many well-known pitfalls exist. These include self-censorship, higher risk-taking behavior, and stereotyping which can lead to defective decision-making and reduced performance.

However, communication, shared mental models and beliefs can help to avoid those problems and therefore are seen as crucial aspects in team decision-making [START_REF] Neck | From Groupthink to Teamthink: Toward the Creation of Constructive Thought Patterns in Self-Managing Work Teams[END_REF]. As a consequence, suitable methods and tools must be provided to ensure such beneficial conditions when empowering teams to participate in process (re)engineering. One of the methods that may support team decision making in this way is LEGO® SERIOUS PLAY® (LSP).

2.2

The LSP method Lego Serious Play® (LSP) was originally developed to facilitate the strategy building process of the LEGO Company. LSP can best be described as a facilitated workshop where participants respond to tasks by building symbolic and metaphorical models with LEGO bricks and subsequently presenting them to the other participants. The LSP method is built on some basic values, like "The answer is in the system", "Everyone has to express his/her reflections" and "There is no ONE right answer". Partici-pants are enabled to interact in a non-judgmental, free-thinking and playful way and can therefore work towards developing a common understanding, creative ideas etc. [START_REF] Kristiansen | Articulation of tacit and complex knowledge[END_REF][START_REF] Hansen | Get a Grip on Sense -Making and Exploration Dealing with Complexity through Serious Play[END_REF]. LSP is founded on four main constructs:

1. the importance of play as a way to learn through exploration and storytelling 2. constructionism 3. the hand-mind connection as a path for creative and expressive thinking 4. the role of the different kinds of imagination

In a typical LSP workshop the participants are first asked to build their perception of a particular problem. In the creative and spontaneous building process that follows, the participants give meaning to their models. Afterwards each participant explains the underlying story of his or her model to the others. Participants must respect the model and its meaning but they are allowed to ask questions to clarify details. In an LSP workshop the individual models can be used to build a shared model, to draw connections, and to create a landscape with so called 'external agents'. In a concluding reflection part the group creates insights [START_REF] Kristiansen | Articulation of tacit and complex knowledge[END_REF][START_REF] Hansen | Get a Grip on Sense -Making and Exploration Dealing with Complexity through Serious Play[END_REF][START_REF] Frick | LEGO®SERIOUS PLAY® -A state of the art of its applications in Europe[END_REF]. The whole model can be the basis for playing, for analyzing particular scenarios, and finally extracting guiding principles [START_REF] Kristiansen | Articulation of tacit and complex knowledge[END_REF].

The LSP method has already been applied to a multitude of problems [START_REF] Hansen | Get a Grip on Sense -Making and Exploration Dealing with Complexity through Serious Play[END_REF][START_REF] Frick | LEGO®SERIOUS PLAY® -A state of the art of its applications in Europe[END_REF][START_REF] Hadida | Let your hand do the thinking! Lego bricks, strategic thinking and ideas generation within organizations[END_REF][START_REF] Jentsch | Strategy and Innovation for the Production Systems of SME[END_REF][START_REF] Jentsch | Flow and Physical Objects in Experiential Learning for Industrial Engineering Education[END_REF]. Considering the mechanisms and theories inherent in the method it can be expected that it also lends itself to positive team decisions in the context of reengineering any kind of processes.

Methodology and propositions

A case study approach was chosen as the research methodology. A case study can be described as the "detailed examination of a single example of a class of phenomena" [14, p. 34]. It is useful in providing hypotheses, which may then be tested systematically later on with a broader empirical basis [START_REF] Flyvbjerg | Five Misunderstandings About Case-Study Research[END_REF].

A case study research design usually has the following components displayed in table 1 [START_REF] Darke | Successfully completing case study research: combining rigour, relevance and pragmatism[END_REF][START_REF] Rowley | Using Case Studies in Research[END_REF][START_REF] Yin | Case study research; design and methods[END_REF] with its equivalents in our particular case.

Table 1. Research design

Component

Equivalents The study's questions Is LSP a suitable tool to support also the collective / participative reengineering of a more or less creative process like product development?

The study's propositions LSP supports collective decision making when reengineering a design process -typical deficiencies are avoided. Participants are satisfied with the process. Participants show a high identity with the result.

Component Equivalents The study's units of analysis

The reengineering of a "product development lifecycle" process with a certain number of participants from different departments.

The logic of linking the data to the propositions Observed and self-reported qualitative variables lead to conclusions regarding the propositions.

The criteria for interpreting findings Number of observed groupthink events during the reengineering process, self-reported satisfaction, identification and acceptance from the participants, tangible outcome of the reengineering process.

3

Case study analysis

Case description

This case study examines the impact of LSP as a tool in creating an effective Product Development Life Cycle (PDLC) process in which it is necessary to clearly define each functional role and respective responsibility. The company involved in the case study is a global medical device development and manufacturing business with headquarters in the USA and a number of operations worldwide including Ireland. The company had undergone a period of rapid growth and this resulted in functional areas roles and responsibilities both overlapping and separating from each other. The result of this rapid growth led to confusion around functional roles and responsibilities. However, development teams are required to work very closely together to support PDLC processes in order to reduce time to market. Of interest to the researchers was whether or not improvements to the PDLC process could be made using LSP tools and techniques. To this end, a one-day workshop was convened. The workshop was conducted off-site, over a seven-hour period and was facilitated by a certified LSP facilitator. Detailed observations were made throughout the workshop by another independent person. At the end of the day feedback was elicited from participants using group reflection exercises and an individual questionnaire survey. The workshop design followed the typical LSP setup as explained in chapter 2.2. At the outset, the participants declared that they had an open mind and no particular expectations at the start of the workshop. They were aware that the workshop involved the use of Lego and that the theme was defining functional roles and responsibilities during New Product Development Life Cycle (NPDLC) processes. The purpose was to create collaborative clusters working together towards a common goal. The challenge included how best to provide an authentic collaborative environment through learning activities to achieve a set of objectives. The Groups involved in the Workshop were from three functional areas in the company and involved eight senior management participants (2 female and 6 male). The groups comprised the following: Each member was allocated an LSP kit and very quickly became familiar and comfortable with the workshop requirements. The 3D models built by each individual/group served as a communication tool and provided for a collaboration space to develop group responses and to trigger questions, see as an example fig. 1. From an observer's perspective this provided for peer-input and evaluation exercises and allowed knowledge sharing amongst the wider cohort. Obviously the 3D models acted as useful representations of proposed processes and allowed areas of overlap, redundancy, gaps and complications to be identified in a transparent way.

Evaluation results

The feedback from the participants provided in the questionnaire centered around the following themes of collaboration challenges, resolution techniques and the resulting benefits. In answering the question "Is LSP a suitable tool to support the collective/participative reengineering of a more or less creative process like product development?" the following comments can support that this is the case.

 "Getting the group to engage openly and honestly with each other"  "Ensuring everyone engaged openly and honestly in group discussions"  "A lot of conflict within the group -was aware of this before the session and wasn't sure if it would work"  "Pre-defined opinions strongly held"  "Integrating models developed individually with the group models"  "Differing views on process descriptions"  "Definition of roles and responsibilities. Understanding of the process steps and stages from different departmental prospective in the PDLC"  "Understanding/not knowing other members needs and perspectives"  "Lack of clarity of roles"  "Not all aligned back at the day job"

The participants explained how they resolved the challenges of working in a group:

 "Using the Lego we built models current and future that facilitated very good discussion"  "Open communication, respect the viewpoint of others, spoke about the model and addressed questions to the model and not to the person presenting"  "Through sharing ideas through building and discussing ideas through the models"  "Rotated the presentation role, ensured everyone spoke to the model so that it wasn't personal"  "Everyone respected the others opinion within the context of the exercise"  "Model was independent of personalities and functions/departments" In answering the study's proposition that LSP supports collective decision making when reengineering a design process and hence typical deficiencies are avoided, the following comments were made with respect to group/team engagement.

 "Having the three groups working together without any disruption and focused on one objective"  "Developed closer ties between individuals and teams".  "Building on the existing relationship between all members of the team"  "Establishing group views for later discussion" Those comments are supported by the independent observer who didn't identify any deficiencies in the group decision making process.

With respect to understanding roles and responsibilities, the participants rated understanding of each other's roles and responsibilities as a benefit and also highlighted the positive aspects of the experience. In terms of shared understanding for future growth, the participants recognized the need for growth and progress and felt this could be achieved through LSP. Benefits gleaned from the LSP experience included: "Listening to current state of affairs and preferred future state"; "Hearing other ideas and perspectives"; "Individuals take visual ideas from one another"; "Discussing ideas and challenges"; "Agreeing that future/continued actions are necessary to create an agreed strategy"; "More focus on the bigger picture"; "Bonding and alignment of views"; "Shared understanding was developed".

Advantages and Disadvantages

Whilst the participants appreciated working with visual tools and clearly identified the 'real-world' relevance of replicating industry scenarios and problem-solving activities through 3D models they were aware of the time required by this process. They also stressed the need for follow-up to implement the new model in the form of a written plan of action. It was also suggested that non-attendees may not take the process seriously so translating the output to the organization in a suitable manner would be important.

All the participants were satisfied with the workshop experience and agreed that working with LSP provided them with a deep learning experience and engagement with the group. The positive dynamic and confidence of all grew and they came to a shared understanding on the team goals as a result. The reasons for the positive outcomes fit with former research results proofing that the LSP methodology gives ownership to people, provides the possibility to express clear visions and leads to a shared understanding by an easy modelling technique.

Conclusion and future research

The responses from the participants indicate that incorporating LSP as a support tool for NPDLC resulted in extremely engaged and creative managers who became absorbed in a process of improvement. The responses also highlight that the objectives set at the start of the workshop were achieved. The results suggest a deeper understanding of NPDLC roles and responsibilities than previously. Also engagement with the process was enhanced as participants were required to use higher level cognition. The groups also rotated the leadership role and this facilitated group problem solving, communication and improved leadership skills. Perceived disadvantages of LSP were minimal.

The company intends to address and resolve gaps and misconceptions in the current PDLC process with respect to roles and responsibilities. It was agreed that an action plan would be developed and that a follow-up LSP workshop and review would take place in 12 months' time to determine what process improvement if any was achieved.

Further research will focus on evaluations on whether or not teams can function more effectively under different conditions. Variables to be considered may be problem's complexity and tangibility, group's heterogeneity, individuals' background, experiences and attitudes, situational parameters etc.



  Research & Development (4 personnel)  Regulatory Affairs (2 personnel)  Design Assurance (2 personnel) The workshop program involved (1) the introduction of participants and a brief introduction to LSP rules; (2) LSP skills building; (3) the building of individual and shared model(s) of the as-is-product development cycle; (4) the building of role models (group work); (5) the building of a shared model of a future product development lifecycle (aspiration) and the assignment of the different roles and their responsibility; (6) a final discussion with a conclusion and reflection and the agreement on further steps.

Fig. 1 .

 1 Fig. 1. Shared model of the future product development lifecycle