) ; Le Masson

Benoît ) ; Weil

Fabien Jean
email: fabien.jean@mines-paristech.fr

INVERSE TECHNOLOGY C-K IN ENVIRONMENT C-K TO OVERCOME DESIGN FIXATION

Keywords: Design theory, C-K theory, fixation effect, Technology, Environment

Formal theories of design have described design as a quest for the fit between two spaces such as form-context, solution-problem, structure-function and presently Technology-Environment (T-E). On the contrary, existing methods tempt to focus on E; most engineering disciplines serve T; designers are consequently left barehanded to apply formal principles. More specifically a design method should help to overcome design fixations and enable to steer T-E double exploration. First we extend Concept-Knowledge formalism by defining the inverse C-K of a considered C-K, i.e. the knowledge base is put into question to formulate a new initial concept and the initial concept has an assumed logical status to become the new knowledge base concept. In this configuration, one C-K can benefit from expansions of the other. Second a method is deduced by applying this principle to the T-E framework: designers should steer their exploration by drawing simultaneously T C-K and E C-K. Four empirical cases are analysed. The results suggest that the method enables to identify a maximum of fits before converging on one when used from the start or can provide defixating knowledge expansions when not.

1 INTRODUCTION Alexander (1964) observed that houses in indigenous civilisations fitted well to their environment despite they seem rudimentary to our eyes, whereas sophisticated modern houses tend to be disappointing regarding their fit. Designing artefacts deals with designing their fit to their environment and even if the idea seems simple, it has induced lots of work from the point of view of formal theories -section 2.1-as well as methods -2.2. Technology intensive firms such as an aerospace tierone supplier -3.2-are not at rest with these difficulties which interact with organisational issues. This paper describes a dual technology-environment exploration method -3.1-and analyses the results of its experimentation -4-in order to contribute to formal theories as well as their methodical implementation -5. In following sections T stands for Technology, E for Environment.

LITTERATURE REVIEW AND RESEARCH QUESTION

Technology-Environment Fit in formal theories

Starting design from knowledge on the Environment (E) the product should fit with

In Systematic Design [START_REF] Pahl | A critical review of general design theory[END_REF]), the customer and the need to be addressed are defined in the specifications which are the input for Conceptual design. This fixates knowledge on the environment the product should fit with in order to focus on technological efforts until the end of product design. Design For X (DFX) techniques, where X stands for a particular life-phase or a virtue that the product should possess, enable to broaden the knowledge on the environment of the object being designed in order to make the best technological choices, notably they may consider environments in and out firm boundaries [START_REF] Holt | Towards an integrated approach to "Design for X": an agenda for decision-based DFX research[END_REF]. Is that possible to reverse the process by defining the technology before the market is identified, even before a product is envisaged?

Starting design from knowledge on the Technology (T) which will compound the product

Reverse Inventing has been proposed as a method to regenerate opportunities in technology-intensive firms by identifying new markets in which their core technologies are potentially valuable [START_REF] Glaser | TRIZ for reverse inventing in market research: a case study from WITTENSTEIN AG, identifying new areas of application of a core technology[END_REF]. In the same stream, D4 method enables in the case of exploratory partnerships to prospect new customers, to give value to a technology and to outline new perspectives of development [START_REF] Gillier | Co-designing broad scope of technology-based applications in an exploratory partnership[END_REF]. Where the first utilizes TRIZ contradictions and inventive principles, the second utilizes technology properties and generic functions to reformulate T knowledge to steer E exploration. If design may start equally from T or E knowledge, what is the formal explanation for such a contingent factor for designers? [START_REF] Alexander | Notes on the Synthesis of Form[END_REF], described design as an "effort to achieve fitness between two entities: the form in question and its context". In his vision, designers should not focus only on the form but on the ensemble form-context. This framework has then be reformulated as problem-solution fit [START_REF] Simon | The structure of ill-structured problems[END_REF] or geometry-functions fit [START_REF] Shapiro | On the role of geometry in mechanical design[END_REF]) -and we shall add T-E. Yoshikawa's General Design Theory (GDT) expresses Fitness by a mathematical mapping from the artefact description to function -i.e. from T to E-(Reich 1995). In Axiomatic Design [START_REF] Suh | The principles of design[END_REF]), Customer Attributes (CAs) -i.e. E-are translated in Functional Requirements (FRs) and Constraints (Cs) -i.e. reformulated E-which should be addressed by Design Parameters (DPs) -i.e. T. FRs differ from Cs which dependence is not affected by designers' choice -FRs are more malleable E knowledge than Cs. Hence, Fitness occurs between the range of a FR and the range addressed by DPs. If the Independence Axiom is respected -the E knowledge is well structured-each FR is addressed by a DP and the maximal FR range can be addressed rather than a compromise between two or more FRs -the T-E Fit is better. Moreover DPs must be chosen so that there is no conflict with the Cs which might be either Input constraints or System constraints [START_REF] Suh | Axiomatic Design Theory for Systems[END_REF]. System constraints are typical of the E knowledge modern industries are facing and Axiomatic Design gives few explanations on how to deal with them whereas Input constraints are addressed when translated in FRs boundaries. Couple Design Process (CDP) puts emphasis on the dual evolution of specifications and design solutions through an iterative process [START_REF] Braha | Topological structures for modeling engineering design processes[END_REF]. In the "basic model", Fitness occurs between the Functional Descriptions fi and the Structural Descriptions di in Closures. More specifically, the good fit between ICED15 a closure of functional descriptions Uf(fi) and a closure of structural descriptions Ud(di) depends on the availability, richness, and coherence of knowledge. In CDP, i.e. the real design model, iterations concern a couple of functional and structural descriptions <fi,di>. Hence the basic model concerns particular cases where decoupling can be done. Therefore section 2.1.1 describes decoupled examples where E establishes the specifications for T, section 2.1.2 describes decoupled examples where T features steer E exploration. Presently we see that coupled cases have been addressed in formal theories to the point that recent Concept-Knowledge formal language would not even distinguish T from E [START_REF] Hatchuel | CK design theory: an advanced formulation[END_REF], unless, as it is the purpose of this paper, we distinguish T knowledge Kt from E knowledge Ke. This gives our theoretical framework as illustrated Figure 1. At this point we are not sure that both Kt and Ke expansions are possible in a single process. What method could guarantee this? From an organisational standpoint, difficulties include Kt and Ke keepers are often spread within the firm (engineering and research for T ; marketing, intelligence, sales for E) or between firms (firm A is a supplier of firm B, firm A possesses Kt, firm B possesses Ke).

Technology and Environment designed simultaneously in formal theories

Methods to steer Technology-Environment dual expansion

Reaching Technology-Environment Fit

Because of the latter considerations, System Engineering has focused on both formalisms (definition of system, system of system) and organisational implementations (system life cycle processes and activities) [START_REF] De Weck | Engineering systems: meeting human needs in a complex technological world[END_REF][START_REF] Haskins | Systems engineering handbook[END_REF]. One famous System Engineering tool namely Technology Readiness Levels (TRLs) was invented at National Aeronautics and Space Administration (NASA) to formalise how new scientific knowledge (TRL 1) found applications (TRL 2) and then the technology is demonstrated in prototypes with growing fidelity to the intended real environment (TRL 3 to 9) [START_REF] Mankins | Technology readiness levels[END_REF][START_REF] Mankins | Technology readiness assessments: A retrospective[END_REF]. In a first assumption illustrated in blue in Figure 2, once the target environment has been fixated, efforts are put on making work the technology in this environment by testing more of its features at each TRL [START_REF] Högman | Applying stage-gate processes to technology development-Experience from six hardware-oriented companies[END_REF]. However TRL assessment methodologies (ASD(R&E) 2011) clarify that technology developer and integrator should collaborate at least to understand the critical features of the environment for the new technology, at best to design jointly technology and environment as illustrated in green in Figure 2 (see Comanche helicopter versus other cases in (GAO 1999)). Parameter Analysis methodology has been translated in C-K theory of design operators and characterised as "steepest first" approach [START_REF] Kroll | Steepest-first exploration with learning-based path evaluation: uncovering the design strategy of parameter analysis with C-K theory[END_REF]. In other words, it ensures convergence to one T-E Fit but it does not prevent designers from design fixation (the cognitive bias has been broadly studied as reviewed in [START_REF] Linsey | A study of design fixation, its mitigation and perception in engineering design faculty[END_REF]). Methods to broaden the exploration and overcome certain specific fixations are reviewed hereafter.

Fixation on Technology at the expense of Environment

Management literature has broadly encouraged to design technology in a separate process than products, notably by adopting a stage-gate approach [START_REF] Cooper | Managing technology development projects[END_REF] which could be adapted from TRLs [START_REF] Högman | Applying stage-gate processes to technology development-Experience from six hardware-oriented companies[END_REF]. Freed from market constraints, technologists seem more able to explore. However such approaches can easily fall in the trap of low 'value creation / research spending' ratio and are hardly sustainable. Edison's labs were highly criticised as such.

Fixation on Environment at the expense of Technology

It has been recommended to focus on business model to augment competitiveness by avoiding long technology development cycles [START_REF] Lee | A MORPHOLOGICAL APPROACH TO BUSINESS MODEL CREATION USING CASE-BASED REASONING[END_REF]. For instance Customer Value Chain Analysis may help to focus on value proposition [START_REF] Donaldson | Customer value chain analysis[END_REF]). However such DFX methods have been said to lack a holistic approach because applied separately they fail at helping the designer finding compromise between divergent constraints [START_REF] Meerkamm | Design for X-A core area of design methodology[END_REF]. In other words, moving from a fixation on one environment to another is not a design rationale to reach a satisfying fit. User Centered Design (UCD) has been proposed to refocus design on human-machine interactions as advances in technology lead to poorly usable products [START_REF] Carroll | Making use: scenario-based design of human-computer interactions[END_REF]. As UCD fixates on usability whereas affective aspects are as important, Product Ecosystem for User eXperience has been proposed to ensure that a still broader environment is explored beside T [START_REF] Zhou | Fundamentals of product ecosystem design for user experience[END_REF]. We see then that methods to stir E explorations are still debated whereas formal theories claim it is not enough in all cases as designers need to explore T as well.

Methods to lead dual expansions

Product/Service-System (PSS) design is a recent attempt at avoiding design fixation on either business or engineering [START_REF] Sakao | Product with service, technology with business model: Expanding engineering design[END_REF], notably by moving the value proposition from physical products to functions [START_REF] Wallin | Developing PSS concepts from traditional product sales situation: the use of business model canvas' in Product-Service Integration for Sustainable Solutions[END_REF]. PSS puts the emphasis on the necessity to design coupled products and services in an integrated way [START_REF] Cavalieri | Product-Service Systems Engineering: State of the art and research challenges[END_REF]. These methods tempt to compensate a lack of tools for practitioners without providing a formal understanding and may not help at most early stages. Design rationales have been described in the case of generic technologies development, i.e. technologies which address disjoint markets by realising their common functions [START_REF] Kokshagina | How design theories enable the design of generic technologies: Notion of generic concept and genericity improvement[END_REF]. They differ in the way the T knowledge domain for the generic concept is acquired. These strategies to define a generic concept are one approach to perform T-E double exploration, can we define others? Can we reach a more general theory for T-E double exploration? How should designers steer the double Technology-Environment exploration to prevent fixation on Technology, Environment or one poorly valuable Technology-Environment Fit?

METHOD

Method experimented: Segregating Technology (T) and Environment (E)

To avoid fixation on either T or E by dissociating their explorations, the method considers two C-Ks:

Four cases grounded at SAFRAN

SAFRAN is a conglomerate of tier one suppliers in space, aeronautics, defence and security. The companies within SAFRAN are technology intensive, they utilise extensively System Engineering and TRLs. The first case is the exploration of energy-non-dissipative concepts without a specific method. The second case is the exploration of an energy conversion technology which led to the descriptive model hereupon. In the third case, the model is employed prescriptively to make two separate explorations benefit from one another. The fourth case is an exploration steered from the beginning with the model, hence consolidating the method.

Data

Data collection

In accordance with intervention-research methodology [START_REF] David | From actionable knowledge to universal theory in management research[END_REF], one searcher was fully employed among practitioners in the empirical cases in order to gather all possible data and process epistemic loops. In short, every loop entails providing theoretical scaffold by researchers to model SAFRAN reality, refining those models collaboratively with SAFRAN, and experimenting

ICED15

those models. The searcher joined the Innovation Head Office team with the mission to coordinate some explorations and eventually steer them towards structured projects. Data collection summarised in Table 1 was then possible at very early phases of design in real industrial situations.

Data analysis

Our goal is to test the proposition that the dissociating T-E method presented in 3.1 prevents fixation on either T or E (P1) and prevents fixation on one T-E Fit (P2). (P1) implies that knowledge on both T and E is explored, (P2) that various {T,E} couples are explored. Consequently our metrics are knowledge incremental expansions in both domains (δKt and δKe) (P1) and T-E Fits explored (F1, F2...) (P2). We do not count concepts of T-E Fits identified but left unexplored.

RESULTS

Cases analysis

None Dissipative Energy Converter (NDEC) -when a single idea is explored and killed

Background -initial knowledge base. Related to the global energy crisis (Ke0), explorations were lead on energy efficiency and the concept "NDEC" was identified as applicable to Company E (CE) products. A first energy conversion (EC1) was identified to replace current dissipative energy conversion (EC0) (Kt0). This draft fit was summarised to the Innovation Head Office (IHO) (F0).

Single C-K intervention. An expert on such energy conversion technologies is consulted; the power to convert is estimated (+1δKe). The replacement would highly deteriorate weight (+1δKt). The proposition "...hybrid EC0-EC1" is added to the Initial Concept and explored (F1). As energy is dissipated through different channels (Ci) (+1δKe), the proposition "...in C1" is added as only one is suitable (F1'). The energy saved is estimated (+1δKt). Cost avoided for airlines is deduced from technology efficiency (+1δKt), current energy supply cost and average consumption (+2δKe). Finally a formal meeting oblige to deep the overall energy at stakes (+1δKe) and to compare with an alternate patent (+1δKt). During the meeting two alternate energy conversion types are identified as long-term perspectives (+2δKt). No good fit has been found and the exploration is ended.

New Energy Conversion Technology (NECT) -when fixation on technology is overcome by taking pitched objectives by a supplier as true propositions

Background -initial knowledge base. A New Energy Conversion Technology (NECT) had been identified by Company A (CA) to harvest wasted energy. After few explorations of the basic principles (Kt0), CA collaborated with Company B (CB) to identify three locations where wasted energy could be harvested thank to this technology. CB identified one concept to use the harvested energy but its lacking availability in time was considered as a show stopper (Ke0, F0).

First steps with single C-K. CA presents the exploration to the IHO who asks for more applications to be explored among other companies. The Initial Concept is formulated "Energy harvesting with NECT" and adds "...in E1" as a separate project at CB could provide E for NECT. The project manager is interviewed and adds the proposition "...to make my product under development energetically autonomous" and shares knowledge about its product energy grid (F1,+1δKe). But the exploration stops as integrating NECT would delay the project. CA turns to Company C (CC) who explains two new locations for harvesting energy (+1δKe) and proposes many energy usages. The latter raise the question of NECT thermal behaviour, weight and power.

The birth of our method. A three-step seminar is organised, step E is a discussion with 4 additional product experts, step T is Supplier S (S) presentation of preliminary studies on NECT and step D is a debriefing without S. In step E, experts reveal one major issue justifying a first energy usage (F2, +1δKe), and proposes a new energy usage without details. In step T, S answers the question of NECT thermal behaviour (F2, +1δKt), range of weight (+1δKt), present possible configurations ICED15 (+1δKt), and gives its objectives of power. Next move is a workshop on the concept "Value of NECT for customer" which interprets S power objectives as true in K-base and reviews all the propositions of energy usages. Two generic criteria to choose energy usages are added as well as a client valuing criterion (+3δKe). We should notice that this was tried before but fixation on certain features of NECT prevented it. Then a group of experts is consulted on a specific proposition and establishes its certification conditions (F3,+1δKe). A manager is interviewed and shares its constraints from clients and power required on another proposition (F4, +2δKe). Finally CC provides the power required and TRL in current configurations and future configurations for a former proposition (+2δKe, F5).

Agile usage of our method. The next move is various interviews discussing first "value of NECT" and then "Demonstration of NECT". A product manager in another company confirms a significant weight loss as well as three other benefits if NECT was integrated and gives a critical demonstration required (F0, +1δKt, +3δKe). Similarly an expert at CB shares a value criterion for clients and one required demonstration step (+1δKt, +1δKe). Finally the workgroup presents the exploration to top managers and a specific budget is granted.

Disruptive Technology for an Identified Customer (DTIC) -when value model gap prevents validation at the gate because of Technology fixation

Background -initial knowledge base. Very disruptive and holistic explorations were led within CB (Kt0, Ke0). A summary is supplied to IHO who observes that the exploration is too broad (the concepts overwhelmed SAFRAN competences and markets) and too fuzzy (confusion between concepts and technical solutions) to launch a project. Still high potential is perceived.

Intervention with single C-K. The fuzzy summary and related investigations are translated in a C-K diagram. The C-K formalism enabled to represent both E and T continuously. Questions to fill knowledge gaps were added. The diagram is presented to CB management in order to enhance the reasoning and jointly prioritise concepts. CB R&T manager actively engages in the reasoning as expected and shares knowledge on estimation of fuel burn property (F1, +1δKt), related previous explorations (F2, +1δKt), one operability property, (F3, +1δKt), noise-induced constraints (F4, +1δKe), fluid tightness property (F5, +2δKt), current technology velocity, existing technological alternatives, predictive maintenance properties, one client value criterion (F6, +4δKt, +1δKe), one significant failure-mode, current security properties, one technological alternative (F7, +3δKt), energy required, one technological alternative, client usage (F8, +2δKt, +1δKe), flying procedures, certification constraints (+2δKe). The C-K is then reshaped to integrate this new knowledge. In the meantime, CC starts the development of a DTIC closely related but IHO refuses to fund because of a neglected value model -i.e. there is a big Ke gap to close. The C-K is then modified and presented to a CB pre-project manager so as to close this gap. The manager shares two other operability properties, velocity problem, maintenance property, user practices (F6, +4δKt, +1δKe), one structural failure mode, non-valuable environment, integrating system evolution (F7, +1δKt, +2δKe).

Intervention with our method. As the latter failed at completing CC value model, an E C-K with the Initial Concept "Value of DTIC" is started. The first proposition added to the concept are "...to reduce field length" and "...to increase the number of operable Airports". These properties lead to simple calculations and sharing an airport data base (F6, +2δKe). At this point that data fails at providing a business case. More useful information is a Target Airport (TA) for the Identified Customer (IC) (F6, +1δKe). So a T C-K is started with the Initial Concept "DTIC"+"...to ensure TA operability". Three technologies (Ti) previously integrated by IC are found (F6, +3δKt). Back to the E C-K, this new knowledge enables to add the propositions "...by Ti" which obliges to decompose phenomena in E to explain their value (F6, +2δKe). Later a list of significant airports (Ai) for IC is obtained (F6, +1δKe) which enables to change the proposition "...to increase the number of operable Airports" into "...to ensure Ai operability", ensuring a viable value model to start the project.

New Energy Transport Technologies (NETT) -when technology and environments knowledge keepers break the rules together methodically

Background -initial knowledge base. A technology allowing to transport energy usually not transportable was explored (Kt0) as well as five energy sources and six functions requiring such type of energy distant in a plane (Ke0). Then the concept of "NETT smart-grid" was defined (F0) and CC submitted a summary to IHO which regretted that technologies needed were too immature.

ICED15

Intervention with our method. The T C-K is started by the Initial Concept "Demonstrated NETT" which leads to discover previous explorations on another disruptive energy transport technology led at Company D (CD) (F1, +1δKt). As previously acquired knowledge on energy nodes was too shallow, the E C-K is initiated by formulating the concept "Value of NETT". Four products at CB and Company E (CE) are identified as potential environments (F1, +4δKe). In a meeting involving the four companies CC and CD present the technology opportunity -setting Kt0-, then CB and CE confirm their interest and add a product, explain two major issues at stake, two power ranges, each product expected time-to-market and client and three new energy sources (F1, 18δKe). Then a workshop compound of T step, E step and one Idea Generation step is organised. In T step, CD presents its efforts on two commercialised technologies (+2δKt) and the disruptive energy transport technology main features (F1, +1δKt). In E step, CE presents the main features of its products: their common architecture, their differentiating design parameters and value criteria for clients (+3δKe). We learn from CB presentation the energy transport details on one known architecture and a new architecture based on energy transport (+2δKe). In Idea Generation step, five main concepts are identified and explored in the workshop (F2, F3, F4, F5, F6, detailed data analysis not performed at the time of writing). Besides, four complementary technologies are evoked (+4δKt). Design theories insist that both T and E should be explored; we find that it is the case with or without our method. However the method ensures that more different Es are explored and provides a better control to face fixation. Some methods such as Parameter Analysis focus on converging on one fit without addressing the risk of missing better T-E Fits because of early fixation. Case 1 is typically in this situation. At the opposite when our method is employed, four different T-E Fits in Case 2 and seven in Case 4 are explored before starting convergence on a specific fit. Other methods fixate on either T or E. In Case 3 fixation on T when value for E was low (19 δKt, 0 switch) was overcome with the E C-K and then switching C-Ks enabled to explore even more Es. E is explored with more relevant focus regarding the fit being explored. Ts are described with physical phenomena instead of functions because generally functions are T-E Fits. This enabled new T-E Fits to be explored in all cases.

Summary of results

CONCLUSION AND DISCUSSION OF THE CONTRIBUTION

Main findings are that our structured Technology-Environment (T-E) approach increases innovative design quality on both T, E and the coupling between T and E: more variety and originality on T and E concepts, more knowledge on T and E and more T-E Couples explored. More specifically, many Es are explored rather than fixating on one like most methods. Designers are not obliged to focus on pairs {single T, single E} but can envisage generic technologies. Knowledge structure is also improved as Ts are described in a more abstract and generic way and Es are deeper understood.

The method enables new forms of collaboration. Usual processes tend to restrict marketing actors to E exploration and engineering designers to T exploration. With T-E processes all actors can participate to both explorations if they obey the design rules (either T knowledge or E knowledge as invariant). This ensures that they adopt a relevant focus to contribute to the exploration. Similarly supplier and buyer find a model for collaboration... this paves the way to creative collaboration.

We believe this represents a significant extension of C-K Theory of design by determining how two C-Ks can interact and share benefits of their expansions. Previous attempts would allow ICED15 interactions only with an intermediary space [START_REF] Kazakci | A model of CK design theory based on term logic: a formal CK background for a class of design assistants[END_REF] or focus on generating a common concept [START_REF] Gao ; Gillier | Better Management of Technology Development Can Improve Weapon System Outcomes[END_REF]. Our formal proposition of inverse C-Ks -section 3.1-seems to allow two C-K to defixate one another and facilitate learning. This should not be restricted to the T-E framework in further research. Other design theories proposing models for collaborations (Product Social Institutional framework, computational models etc.) may also benefit from this work. In fact this work may provide a base for bridges between design theories and other disciplines such as project management, marketing or organisational studies.

Figure 1 :

 1 Figure 1: theoretical framework of Technology-Environment Fit

Figure 2 :

 2 Figure 2: Concept and knowledge expansion for each interpretation of TRLs

Figure 3 :

 3 Figure 3: Basic method of dissociated Technology and Environment C-Ks

  of T K0: Value of T in E1, E2… C0: Value of T K0: Demonstrated features of T1, T2…

Table 1 :

 1 Data Collection Summary

		Case 1: NDEC	Case 2: NECT	Case 3: DTIC	Case 4: NETT
	Method	None	In progress model	Prescriptive model	Consolidated Method
	Duration	4 months	15 mths	15 mths	5 mths

Table 2 :

 2 Summary of results

		Case 1		Case 2		Case 3	Case 4
		no	no	birth of the	T and E	single	T and E	built with
		method	method	method	interviews	C-K	C-K	our method
	T-E Fits explored	2	1	4	1	8	1	7
	E and T C-K switches	0	0	2	3	0	2	4
	δKt	6	0	3	2	19	4	8 counted
	δKe	5	2	9	4	8	6	27 counted

The inverse operator of a C-K has not been formally described in literature. In his thesis, Mathias Szpirglas depicts how a piece of knowledge in one C-K can be interpreted as a concept in another C-K. To the best of our knowledge, interpreting a concept from one C-K as knowledge in another C-K has not been studied.


Fabien Jean
email: fabien.jean@mines-paristech.fr

Pascal Le Masson
email: pascal.le_masson@mines-paristech.fr

Benoit Weil
email: benoit.weil@mines-paristech.fr

Engage engineers as designers to generate new meanings in concept generation

The meaning of a product is the profound psychological and cultural reasons people use the product (Verganti 2013). The original meaning resulting from such design-driven research is often compromised when handed-over during concept generation (Dell'Era et al. 2011). Literature gives three models of interactions between designers and their network, i.e. networkers use their knowledge as filter, provide designers with knowledge, or are willing to restructure their knowledge base. Our research question "What is an effective marker event of radical innovation of meaning in concept generation?" is investigated through a multiple case-study comparing 35 marker events in a single organisation. The analysis confirms that meaning attributes are lost when networkers use their knowledge as filter, but surprisingly actors lose attributes even when they adopt methods to prevent it. We also found four main mechanisms for networkers to proactively hand a new meaning. Where the canonical model of gate meeting prevents hand-over to experts, our model of Generative Gate Meetings performs better. Finally engineers play a key role when they elaborate Technology Pretexts which are instrumental for exploring value propositions integrating new meanings. Lastly, we synthesise managerial implications in a process model of concept generation for radical innovation of meaning.

Introduction

The meaning of a product is the profound psychological and cultural reasons people use the product [START_REF] Verganti | Design driven innovation: changing the rules of competition by radically innovating what things mean[END_REF]. Rather than creativity, new meanings invention requires to capture knowledge on product languages by interacting with interpreters earlier than concept generation, i.e. in design-driven research [START_REF] Verganti | Design, Meanings, and Radical Innovation: A Metamodel and a Research Agenda*[END_REF]. However the original meaning resulting from such researches is often compromised when handed-over during product development. As innovation processes should be characterised by their marker events [START_REF] Yin | Changing Urban Bureaucracies: How New Practices Become Routinized[END_REF])including hand-over-, and take into account network creation [START_REF] Christiansen | Making Decisions on Innovation: Meetings or Networks?[END_REF], we identify three types of marker events in literature on the criterion of knowledge exchanges with network. First, idea screening based on their assessment which uses networker's knowledge as filter [START_REF] Cooper | Perspective: The Stage-Gate® Idea-to-Launch Process-Update, What's New, and NexGen Systems*[END_REF][START_REF] Rothwell | Successful industrial innovation: critical factors for the 1990s[END_REF]). Second, providing designers with knowledge from specific types of networkers such as users [START_REF] Kristensson | Tuning users' innovativeness during ideation[END_REF][START_REF] Piller | Toolkits for idea competitions: a novel method to integrate users in new product development[END_REF][START_REF] Hippel | Lead users: a source of novel product concepts[END_REF]), front-line employees [START_REF] Gordon | The idea generation stage of the new product development process: Can key account management systems help[END_REF][START_REF] Judson | Key account vs. other sales management systems: is there a difference in providing customer input during the new product development process?[END_REF], interpreters [START_REF] Verganti | Design driven innovation: changing the rules of competition by radically innovating what things mean[END_REF]. Third, jointly design with networkers willing to restructure their knowledge to adopt implementation ideas of radically new meanings [START_REF] Loch | Managing the unknown: A new approach to managing high uncertainty and risk in projects[END_REF][START_REF] Magnusson | Exploring holistic intuitive idea screening in the light of formal criteria[END_REF][START_REF] Le Masson | User involvement: From ideas collection towards a new technique for innovative service design[END_REF]. But these three models have never been provided with empirical data on the hand-over of new meanings. We then ask the research question: What is an effective marker event of radical innovation of meaning in concept generation? Our method of investigation is a longitudinal multiple case study analysis [START_REF] Yin | Case study research: Design and methods[END_REF]) in a single organisation which conducted vast processes to generate new meanings and had to deal with the exploration of their implementation in products. The cases are analysed under three sets of criteria provided by our conceptual framework: Is it marker event? How effective is it? For which reasons? The analysis confirms that an initial meaning gains attributes -notably at the same time than implementation solutions are generated-and loses attributes -when networkers use technical knowledge as filter-through concept generation, but surprisingly actors do not achieve to keep all attributes even when they adopt methods to do so. We also found four main mechanisms for networkers to proactively hand a new meaning. The canonical model of the gate meeting is a major obstacle when used by experts whereas hand-over are successful when decision makers involve in a design efforts, giving birth to the model of Generative Gate Meetings. Finally, following literature knowledge taxonomy -usage knowledge, technical knowledge, we found that engineers play a key role in both types of knowledge: they formulate technological pretexts which are lever for exploring new value models. This last finding is key for radical innovation of meaning because it is an enabler in providing new meanings with a sustainable value proposition. To summarise managerial implications of these findings, we propose a managerial model -a process-of concept generation for radical innovation of meaning. Finally discussion and perspectives are drawn.

Literature review and theoretical framework

Handing-over the new meaning: a major hurdle in New Product Development (NPD)

The meaning of a product is the profound psychological and cultural reasons people use the product ; it concerns symbols, identity and emotions that are suggested to users or result from their interactions with the product [START_REF] Verganti | Design driven innovation: changing the rules of competition by radically innovating what things mean[END_REF].

Companies who embrace radical innovations of meanings achieve spectacular growth [START_REF] Verganti | Innovating through design[END_REF]. Rather than creativity, new meanings invention requires to capture knowledge on product languages by interacting with a network of interpreters earlier than concept generation, i.e. in design-driven research [START_REF] Verganti | Design, Meanings, and Radical Innovation: A Metamodel and a Research Agenda*[END_REF]. Where [START_REF] Cooper | Managing technology development projects[END_REF] recommended to manage Technology Development in a different process than Product Development to leave more space for exploration, [START_REF] Verganti | Radical design and technology epiphanies: A new focus for research on design management[END_REF] goes further and describes design-driven research, technology research and their entanglement to achieve Technology Epiphanies. However the original meaning resulting from such researches is often compromised when handed-over: from marketing to design [START_REF] Bailetti | Integrating Customer Requirements into Product Designs[END_REF], from marketing to salespeople [START_REF] Hultink | The Effect of Sales Force Adoption on New Product Selling Performance[END_REF], from key account management to market analysis [START_REF] Gordon | The idea generation stage of the new product development process: Can key account management systems help[END_REF], between any functions of the firm [START_REF] Hart | The effectiveness of market information in enhancing new product success rates[END_REF] or from the firm to the customer [START_REF] Anderson | Customer value propositions in business markets[END_REF]. [START_REF] Perks | Characterizing the Role of Design in New Product Development: An Empirically Derived Taxonomy*[END_REF] have reached a taxonomy of the role of design -functional specialism, part of multifunctional team or NPD process leader-and find that design as NPD process leaders -designers interact with all functions of the firm-is the more adequate for radical innovation.

Dell 'Era et al. (2011) have insisted on the importance of language brokering between external designers and managers to prevent the compromising of the original meaning. [START_REF] Verganti | Design driven innovation: changing the rules of competition by radically innovating what things mean[END_REF] recommends an interface manager between interpreters who participate the design research and engineers and marketers involved during implementation. Attempting at a holistic understanding, [START_REF] Gopalakrishnan | Patterns of generation and adoption of innovation in organizations: Contingency models of innovation attributes[END_REF] literature review has identified three approaches to define innovation sequential stages: departmental, activity and decisional. They should be characterised by their marker events [START_REF] Yin | Changing Urban Bureaucracies: How New Practices Become Routinized[END_REF]). In the departmental approach, marker events are a handover from a department to another. However in the activity approach and even more in the decision approach, marker events are less tangible and do not necessarily mean a change in the operational team and stakeholders of the project. Hence next sections will try to consolidate our theoretical understanding of marker events in the design of products with new meanings.

From the idea-screening model to the network expansion model

Marker events may be formalised at gate meetings where the decision to stop or keep on to the next stage of NPD is made, beginning with idea screening [START_REF] Cooper | Perspective: The Stage-Gate® Idea-to-Launch Process-Update, What's New, and NexGen Systems*[END_REF]. In more parallel approaches of Innovation, efficient up-front screening of projects is still considered a critical factor [START_REF] Rothwell | Successful industrial innovation: critical factors for the 1990s[END_REF]). Idea assessment is generally based on systematic criteria, but even when intuitive assessment is used for more holistic and quicker decision, most implicit criteria are identical to systematic criteria [START_REF] Magnusson | Exploring holistic intuitive idea screening in the light of formal criteria[END_REF]. Moreover depending on the idea, decisionmakers may assess the idea or further elaborate it [START_REF] Jean | Convince me or commit me? Avoid the cognitive trap induced by non-human actors in early stages of NPD[END_REF]. Finally, the earlier stages of NPD, often referred to as the fuzzy front-end, require to merge environmental, individual and organisational approaches to be modelled as a decision-making process [START_REF] Reid | The Fuzzy Front End of New Product Development for Discontinuous Innovations: A Theoretical Model[END_REF]. Other limits of sequential decision-making approaches include their unrealistic linearity, the few decisions actually taken at the gates leaving them as informative points for top managers and the heaviness of decision rules for decision makers ; hence the relevance of the network expansion approach [START_REF] Christiansen | Making Decisions on Innovation: Meetings or Networks?[END_REF].

The 1980's Actor Network Theory (ANT) detailed how innovators find a growing numbers of allies through the process of intéressement (Akrich et al. 2002a, Akrich et al. 2002b). ANT has inspired several Innovation processes based on network expansion [START_REF] Christiansen | Making Decisions on Innovation: Meetings or Networks?[END_REF]Varnes 2007, Koch and[START_REF] Koch | The Dynamics and Functions of Self-Organization in the Fuzzy Front End: Empirical Evidence from the Austrian Semiconductor Industry[END_REF]. Are all allies as useful? Next section reviews researches which provide innovators with an accurate answer for certain network actors.

Network expansion to provide designers with knowledge

At a certain stage of the process, the network around the idea includes professional developers who will implement it on the market [START_REF] Kristensson | Tuning users' innovativeness during ideation[END_REF]). Literature has distinguished R&D and marketing actors among them and discussed the flexibility of their role [START_REF] Jin | The nature of NPD and role flexibility of R&D/marketing in a fast growing high-tech setting[END_REF]. It is generally mistakenly assumed that these professional developers know what consumers want, consequently a stream of research has segregated user experience knowledge (held by ordinary users) from technical knowledge (held by professional developers). Firms can involve lead-users who provide ideas with both knowledge types [START_REF] Hippel | Lead users: a source of novel product concepts[END_REF]. They may also shift the locus of innovation [START_REF] Thomke | Experimentation matters: unlocking the potential of new technologies for innovation[END_REF]. The firm provides initial knowledge such as libraries of existing components and an interface so that the customer uses its own knowledge to enrich the meaning of the product through customisation. These toolkits enable more customers to obtain their need faster, increasing the opportunities for firms if they deal with the shift in business model. In late stages, users have the possibility to customise their products through toolkits, integrating their very own knowledge to professional developers' [START_REF] Piller | Toolkits for idea competitions: a novel method to integrate users in new product development[END_REF]. If users are not reachable, front-line employees (salespeople) might be an alternative. They can provide input ideas to NPD -which is easier in organisations with key accounting managers [START_REF] Judson | Key account vs. other sales management systems: is there a difference in providing customer input during the new product development process?[END_REF])-and feedbacks to professional developers [START_REF] Judson | The new product development process: let the voice of the salesperson be heard[END_REF]). Difficulties include short-terms objectives priority on customer knowledge acquisition, lack of transmission mechanism to R&D, and salespeople lack of appropriate skills [START_REF] Gordon | The idea generation stage of the new product development process: Can key account management systems help[END_REF]. Through the KCP process, network expansion may provide any type of knowledge from inside or outside the firm to transform an unknown initial concept into a structured design strategy [START_REF] Ollila | Stepping out of the zone of territorial protection enables open innovation collaboration[END_REF][START_REF] Elmquist | Sustainable development through innovative design: lessons from the KCP method experimented with an automotive firm[END_REF][START_REF] Le Masson | Design theory and collective creativity: a theoretical framework to evaluate KCP process[END_REF]). However a specific type of knowledge enables to radically innovate product meanings, it is product languages obtained by interacting with a network of interpreters [START_REF] Krippendorff | On the essential contexts of artifacts or on the proposition that" design is making sense (of things)[END_REF][START_REF] Verganti | Design, Meanings, and Radical Innovation: A Metamodel and a Research Agenda*[END_REF]. To summarise we see that the network around a new meaning expands to provide it with knowledge. But it may be necessary to modify knowledge structures of the networkers so that they value it as reviewed in next section.

Network creation to design jointly

Ordinary users provide innovators with more radically new ideas of services than lead-users and need not to be forced to integrate technical knowledge to do so [START_REF] Kristensson | Tuning users' innovativeness during ideation[END_REF]. Hence ordinary users' ideas embedding new meaning should not be screened but transformed into implementable ideas by professional developers such as the famous newspaper boy case [START_REF] Le Masson | User involvement: From ideas collection towards a new technique for innovative service design[END_REF][START_REF] Magnusson | Benefits of involving users in service innovation[END_REF]. The case of the Flying Car illustrates also this phenomenon [START_REF] Loch | Managing the unknown: A new approach to managing high uncertainty and risk in projects[END_REF]. From a few initial drawings of a flying car, an innovation manager defines the meaning of flying freely over traffic jams and involves two other skilled actors, and so on the network expands until three concepts clearly arise: LeMans' "DuoSport" three wheeled vehicule, Ardeche's "FlyBike" and Breton's "SkyScooter" foldable wing motorbike. According to section 2.2, they should have eliminated two concepts based on pre-established or intuitive criteria. The model in section 2.3 matches the innovation manager's reaction. Consider another marker event, when Breton reshapes Ardeche's idea of flying motorcycle into a concept achievable with parts from a previous exploratory prototype. This is of different nature because he opens new potential ends for implementation of the initial meaning. One end cannot be assessed against the two other with available knowledge. By building the three prototypes within three separate organisations, they decide to acquire knowledge on each concept as well as knowledge on criteria to screen them. This management practice -where explorations run in parallel are expected of much greater value than sequentially-has been called concurrent exploration (Lenfle 2008, Gastaldi and[START_REF] Gastaldi | Exploration concourante et pilotage de la recherche[END_REF]. If prototyping is not available, to conduct holistic intuitive assessment of ideas, assessors need to generate mini-scenarios of implementation of the idea in order to make use of their experience [START_REF] Magnusson | Exploring holistic intuitive idea screening in the light of formal criteria[END_REF]. This is strong evidence that the network can generate several paths to implement a new meaning, each path adopting different criteria or different weighing of the same criteria.

Summary of the propositions and research question

Our general purpose is to help managers in shaping marker events in their NPD process which favour radical innovation of meaning. Thanks to previous researches, we have reached three theoretical models depicted in Figure 1. They should be matched with dedicated experimentation by asking the following research question:

What is an effective marker event of radical innovation of meaning in concept generation?

We formulate the following propositions to investigate the question:

P1: At a gate meeting (idea screening, go/no-go), the newest meaning is handed over to next stage, P2: When new knowledge is explored, the meaning acquires more novelty through enrichment, P3: When external knowledge is modified, implementation ends for the new meaning are identified.

Research design and method

Overall design

This research is a longitudinal multiple case study analysis [START_REF] Yin | Case study research: Design and methods[END_REF]. This method of inquiry is relevant to our research question because, at this stage of theoretical understanding, construct validity requires qualitative investigation rather than statistical validation. Moreover, "the conduct of a multiple-case study can require extensive resources and time beyond the means of a single student or independent research investigator" (ibid) and our research question requires the finest granularity of data collection. Consequently we focus on a single organisation with the aim to provide with data on every potential marker event of the explorations. For this, a first period of 12 months entailed discussions with the selected organisation and attending few KCP workshops however crucial for a continuous understanding of the cases. In a second period one author had access to previously edited documents and attended all the meetings potentially marker events with allowance to take notes and audio recording during 20 months, plus interviews were conducted within the firm to grasp individual interpretations when needed. The organisation has been chosen of peculiar relevance to our research question. SAFRAN is a corporate conglomerate compound of 12 technology intensive companies. Each company (i.e. business unit) is highly specialised in space, aeronautics, defence or security. Such industries put severe constraints on products so that when a new meaning emerges it has a long way to go before implementation. Plus it is of peculiar interest to draw bridges between radical innovation of meaning and technological innovation [START_REF] Verganti | Design, Meanings, and Radical Innovation: A Metamodel and a Research Agenda*[END_REF]) as technological differentiation is the main focus of SAFRAN strategy, most managers at SAFRAN have an engineering background, but aeronautics is under pressure for a deep change of meaning. Traditional airlines have acknowledged great economical difficulties while low cost airlines go beyond expected limits in service impoverishment [START_REF] Chen | The Two Models Behind Low Cost Products[END_REF]. European Commission has underlined nowadays weak points and renewed objectives for a sustainable civil aviation. Electrical aircrafts, Personal Aerial Vehicules (PAV), drones... the industry is preparing if not already experiencing huge transformations.

Emergence and selection of the cases

In 2012, few months before this research started, two vast processes to renew SAFRAN products meanings were launched. They followed the KCP method as summarised in Table 1. These processes had a double outcome: new meanings and new ideas of products.

Each idea was provided with a leader. The 5 cases analysed in this paper are explorations of these ideas. 2 of them stopped early, 2 of them grew in officials projects which were still going on at time of writing. These cases are of great relevance to our research question because their detailed understanding allows tracing the evolution along the explorations and developments of meanings generated within the KCPs.

Following the KCPs, all these cases started by the redaction of an idea file by experts in Business Units who participated the KCPs. The model was provided by the Innovation Head so as to initiate explorations. However once the files were edited by experts and handed back to the Innovation Head, they were too fuzzy to launch NPD and yet experts had stopped explorations. The following analysis starts from this point where the Innovation Head uses its own human resources to push and steer explorations.

Data analysis

Our goal is to compare the marker events of the cases with respect to our conceptual framework here upon. Our process for data analysis consists of the three steps depicted in Figure 2.

Is it a marker event?

The first criterion analysed is quantitative network expansion.

The second criterion is knowledge expansion. We distinguish two types of knowledge: usage knowledge and technical knowledge. Such taxonomy has proved to be fruitful previously [START_REF] Gillier | Exploring over: the presumed identity of emerging technology[END_REF]Piat 2011, Von Hippel 1986) and was being implemented at SAFRAN during the research period -actors commonly referred to "value model" and "technical feasibility" notably because they are separate assessments both required at gate meetings. If the analysis were lead for each event separately, they have been grouped for presentation purposes in next sections. According to our conceptual framework we distinguish three types of knowledge expansion provided by the network to the idea leader: network's knowledge as filter for the idea leader, network's knowledge shared to the idea leader, and network's knowledge structure modified to envisage the leader's idea.

How effective is it?

It should be noted that our three models are not used exclusively -for instance if the marker event is an official gate meeting we do not exclude meaning enrichment through knowledge sharing from the analysis. This is important so as to allow improvement of these models built from literature.

In accordance with our research question and the propositions presented in section 2.5, our first criterion is the idea leader either complete -one of the networker becomes the leader-, limited -in time or level of involvement-, or null hand-over of the exploration of the original meaning. The second criterion concerns evolution of the meaning through the marker event we code as enriched -new strong attributes are added to the original meaning-, impoverished -some attributes or discarded-or unchanged. The third criterion is whether the network helps the leader by identifying new potential implementations -ideas of products, technical solutions, customer value…-of the meaning.

For which reasons?

For this question, our conceptual framework gives more space. In the network, we distinguish experts at a business unit -engineer if not stated-, coordinators who will support the process with managerial skills rather than technical knowledge and decion-makers whose sponsorship is critical to continue the exploration. However we previously pointed out that literature which has the most holistic approach of network mixes convincement to select the idea and commitment to further elaborate it, that the network should apply the right logic for the right idea, and that some artifacts induce a logic [START_REF] Jean | Convince me or commit me? Avoid the cognitive trap induced by non-human actors in early stages of NPD[END_REF]. We would like to precise these results which have an original approach regarding our present literature review. Hence we believe that the method and artifact of exploration are relevant keys of understanding.

The detailed analysis is provided in appendix.

Findings

Evolution of an original meaning through network expansion

There are various processes to jeopardise the new meaning. In our cases, decision meetings organised as canonical gates had no influence on the meaning of the object (D4, D11). The analysis confirms that technical knowledge may be used as a filter and restrain the initial meaning in different situations (A1, B1, E5). But a striking finding is that when the network tries to preserve all attributes of a new meaning -typically a C-K concept tree enables to represent various alternatives at the most abstract levels-a focus on one dimension of the meaning is adopted (C1, E8). Consequently, the richness -the multiplicity of the attributes of a new meaning-is a major hurdle at handing it over entirely.

The cases provide also strong elements on meaning enrichment. New meaning attributes (sometimes radically new) are generated at the same time than implementation solutions. To do so actors need to induce a design effort to their network either by -conducting decision meetings with a C-K diagram (A3, B3 in contrast with D4, D11), -presenting their exploration to engineers of various technical fields and various business units (D2, D3, D6 part 1, D8, E2, E3), -conducting two steps workshops -knowledge sharing and design (D6, E4). Specifically, we found evidence that engineers enrich meanings when they work at the value model more than when they work at technical solutions (D2, D3, D6, D8 on value, E9).

In summary the original meanings freshly generated during KCPs gain attributes during concept generation, but slowly the newer attributes replace the older (A, B, E). Explorations which adopt tools and methods dedicated to handle a broad value model are not at rest with this issue (D, E).

Decision-making and design reunited in Generative Gate Meeting

In our cases, the initial purpose of gate meetings is not to hand the exploration to a new department. However, when the Innovation Head leads the exploration until it is mature enough to be funded, a planned gate or the perspective of a gate are instrumental in handing back the exploration to business units (C6, D3, D10, E5). But this is not the exclusive mechanism of hand-over; we found it is often the result of actors' proactive attitude:

-coordinators at Innovation Head work themselves to push the exploration because resources are too few in Business Units regarding stakes (A2, B1, C1, D1), -coordinators at Innovation Head steer the exploration so that it matches its own expectations by starting documents to be jointly elaborated with the engineers (A3, B2, B3, C5, D3, D15, E8), -experts proactively involve or even take the lead of the project as they expect it to create value in their business units (B1, C4, C6, D10, E5), -suppliers or research-centre involve as they expect it to create value in their organisation (D10, D13).

What is problematic with the canonical model of the gate is its model of knowledge usage at such early stages. Unfortunately, leaders fail at handing over their exploration to new experts when the latter use their knowledge as filter, acting like if there were asking to take a decision whereas little knowledge shared can be of great importance at this stage (A1, D12, E7). During canonical gate meetings, actors present alternatives of implementations which they identified too late to provide decision-makers with enough information (D10). Such alternatives have a chance when decision makers themselves identify alternatives during the gate meeting (D11, D15); i.e. when they use their knowledge as designers. We found evidence that meetings planned to make a Go/No-go decision can significantly contribute to the exploration by using C-K diagrams (A3, B3 which refocused coordinators on C). C-K diagrams happen to avoid this trap by enabling networkers to switch their type of use of knowledge in a single meeting (A3, B3, C2, E8). In fact they react differently to each concept. They can complete the knowledge base, screen alternatives, suggest new ones, or even restructure them. The analysis suggests that the design of value model is more effective than the design of technical solutions as a mechanism to hand-over the exploration of meaning (A2, B2, C6, D15, E5).

Engineers involvement in value model as critical for radical innovation of meaning

Engineers may either enrich or impoverish a new meaning produced essentially (but not exclusively) by commercials or other non technical functions (B and C came from KCP 2). Still it is relevant to notice that no idea file was handled to employees with a non technical function and that the network expanded prior with engineers even if the Innovation Head puts emphasis on value model requirements. Specifically we observed the following paradox: the value model needs strong technical inputs from the future Environments -customer, specific department, technological system...-of the object being designed -product, technology...-but the knowledge keepers of these Environments are reluctant to give -or seekinformation without a new technology that they could benefit from. Consequently a technological pretext is required to pursue value model exploration and may be provided by a different project team (A1), a supplier (D6) or another business unit (E2). This pretext includes a performance which will either allow value model exploration (D6, E2) or reinforce actors' reluctance (A2, E8). In case of a new technology, the nature of the performance (weight, power...) will have to be designed prior (D6). Hence the role of engineers is fundamental in meaning enrichment along concept generation. Technologies engineers provide with the technological pretext to trigger explorations of various Environments, Environments engineers provide marketers with inputs to value model quantification, and these operations add and remove attributes to the initial meaning being explored.

Proposition of managerial model to implement our findings

We propose to summarise managerial implications of our findings in the model depicted Figure 3. This model is driven by network expansion as depicted in few approaches for innovation. The exploration is steered by a leader who interacts with various actors to enrich his knowledge base until a networker involves in a joint design effort, i.e. he/she is inclined to restructure its own knowledge base -architecture of the product, specifications, plan of experimentation, supplier choices etc. We might also say he/she becomes a stakeholder but in the sense of an individual who accepts to become a design resource in a new project, i.e. the hand-over. This often requires the sponsorship of its manager, hence the role of decision-making in our model. Every leaderdesigner-adopts a design focus. Based on our multiple-case study analysis, we propose the following design focus for radical innovation of meaning: New Meaning The leader steers design-driven research, eventually by embracing the KCP method as in our cases, in order to reach radically new meanings (see examples Table 1).

Existing literature provides great explanations for this.

Technology Pretext In some cases the new meaning will be defined by learning on new technologies. If it is not the case, the leader should seek for technologies that translate the new meaning into artefacts. In both cases, we propose a generic requirement for such a technology which will minimise learning efforts: (1) the phenomenon which is at the interface with adopting Environments -eventually found in hard sciences such as electro-magnetism, semi-conductors, thermodynamics...-, (2) the nature and level of the performance which makes it valuable at a theoretical level -amount of weight, power, efficiency...-.

Value Model The first requirement allows identifying numerous Environments and engaging a dialogue; however we observed that they will not provide designers with enough knowledge until they cope with the second requirement. Hence if the second requirement is not known ex ante, nor can be deduced from existing criteria as it is often the case in established value chains such as aeronautics, joint design iterations are needed.

Opportunities Then we recommend to step-back at the overall exploration, eventually by editing its C-K diagram (section 4.2) and presenting it at a "Generative Gate Meeting" which will recombine the previously acquired knowledge into alternative opportunities. We call an opportunity the combination of meaning attributes -either created in New Meaning exploration or generated in next stages (section 4.1)-, a technology and a value model. The advantage of Generative Gate Meeting on a canonical screening gate meeting is that the less mature opportunities will benefit from feedbacks instead of being erased from the port-folio.

Discussion and perspectives

Our research external validity could be improved by reproducing the experiment in various organisations. Notably our findings on the value model could differ in B-to-C organisations (Only B-to-B at SAFRAN companies).

Usage knowledge is not satisfying because it mixes knowledge on functions (or uses) of an object and knowledge of the user independently of the object. Such confusion takes roots in the most fundamental understanding of design and formal theories are working on it [START_REF] Jean | Inverse Technology C-K in Environment C-K to overcome design fixation[END_REF]. The present paper suggests two minimal requirements on knowledge of a Technology to explore potential adopting Environments prior defining a value proposition, but we believe there is still a lot of work for scholars. As such, we have pointed at the negotiation on who should provide knowledge first. This could draw bridges between design management and open innovation, trust/contract management...

Is it a marker-event?

How effective is it? For which reasons?

Figure 3 :

 3 Figure 3: Our managerial model of concept generation for radical innovation of meaning

Table 1 :

 1 Origin of the cases -two parallel KCP processes

	Screening gate (2.1)	Knowledge sharing (2.2)	Design of idea and criteria (2.3)
	new meaning	meaning selected	new meaning	new meaning	new meaning	new possible ends
	embedded in	for next stage	embedded in	transformed	embedded in	for the meaning
	idea(s)		idea(s)		idea(s)
	Firm screening according	Idea adaptation to	Idea and criteria design.
	to downstream criteria.	downstream criteria.	Network's knowledge
	Network's knowledge as filter.	Network's knowledge reshapes	restructured to adopt the
				the meaning		meaning
	Figure 1: Our conceptual framework: three types of marker events in radical innovation of meaning

Table 2 :

 2 Summary of the cases

	Case reference	Meaning from KCPs	Final Meaning		Time length	Marker events
	A	Zero-energy-waste landing	Simple	and	low	4 months	3
			consumption landing
	B	Ground energy smart grid	Energy local reuse and	2 months	3
		and energy local reuse	auto-maintenance
	C	Low energy and all-airports	All-airports aircraft		5 months	6
		aircraft
	D	Energy harvesting gear	Autonomous gear		20 months	15
	E	Aircraft energy smart-grid	Low consumption aircraft	15 months	8
	TOTAL						35