Chien-Chih Yu
email: ccyu@mis.nccu.edu.tw

Value Proposition in Mobile Government

Keywords: Value proposition, mobile government, mobile services, business model

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

Introduction

Electronic government (e-government, EG) aims at delivering public services to citizens and businesses, leveraging internal productivities of government agencies, and integrating service systems across government organizations by adopting and using information and communication technologies (ICTs) in innovative ways. Mobile government (m-government, MG), with the adoption of mobile technologies, refers to a functional extension of e-government that enables citizens, businesses, and government employees to access government information and services via mobile devices [START_REF] Trimi | Emerging Trends in M-government[END_REF]. While ubiquitous government (u-government, UG) emphasizes on the new form of interactions and transactions that are possibly operated anywhere, at any time, and on various devices and networks due to the utilization of ubiquitous technologies [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF]. The same as for e-government, proposing values to all stakeholders including citizens, businesses, and government agencies have been regarded as a key success factor for promoting the development and use of mobile and ubiquitous government services. Therefore, value proposition and value creation are considered as major objectives and central tasks for the deployment and management of MG/UG related strategies and systems. For simplicity, we use m-government to cover both MG and UG characteristics in the subsequent discussions. On the other hand, business models (BMs) have been noted as proper means to illustrate the concepts and methods for value proposition in both e-business and e-government domains [START_REF] De Reuver | Mobile Business Models: Organizational and Financial Design Issues That Matter[END_REF][START_REF] Janssen | E-government Business Models for Public Service Networks[END_REF][START_REF] Panagiotopoulos | A Business Model Perspective for ICTs in Public Engagement[END_REF][START_REF] Teece | Business Models, Business Strategies and Innovation[END_REF][START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF]. In general, business models focus on specifying structural components and relationships such as actors, services, value, activities, and communications for directing business operations. Therefore, to design and develop suitable EG business model is a key to facilitate value proposition and sustain continuous operations of EG services. Likewise, designing and operating mobile-characterized business models are critical to the success in promoting the provision and usage of MG services, as well as in achieving the goals of proposing and creating public value. In the literature, the emerging issues regarding value proposition and business modeling for e-government and m-government have increasingly attracted research attentions in the past few years. Yet, a unified view and an integrated framework towards illustrating the concepts and methodologies for value proposition and business modeling are still lacking. As a result, the demand of a comprehensive study in this field is significant and strong.

In the literature of e-government applications, various research attempts have proposed some views for identifying value. For instance, identified EG related value include citizen value, business value, employee value, organization value, service chain value, administration value, society value and nation value [START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF]. While focusing on the mobile commerce domain, among very limited research works, one approach of value proposition characterizes business value into three major themes including ubiquitous access, productivity enabler, and positive image [START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF]. Overall proposed value includes instant access, emergency use, enhanced anytime access to new services, and increased productivity. When targeting on the m-government domain, the shortfall of research works dealing with value proposition issues are even more severe. Research literature in this area is very limited and lacks of in-depth investigations. Therefore, the goal of this paper is to propose an integrated conceptual framework for identifying and proposing value to fit the m-government applications. Value proposition with related management issues for providing and delivering mobile public services to citizens, businesses, and government agencies are to be described and discussed. Based on an adaptable EG/MG business model perspective, value, constituents, services, and indicators for MG systems are specified and structurally presented. The proposed value-centric BM framework can then be used to support the planning and evaluation of MG related strategies and systems. The rest of this paper is organized as follows. In section 2, a brief literature review on MG related value is provided. In section 3, an integrated framework is presented with specified value dimensions and elements. In section 4, MG related value, constituents, services, and indicators are illustrated based on a value-centric BM perspective. Concluding remarks and discussions are provided in the final section.

Literature Review

Since previous works focused on value proposition for mobile government are very limited, brief reviews of the research literature regarding value proposition in ebusiness and e-government, as well as in m-commerce and m-government domains are provided in this section to show the current research status and critical issues.

Value Proposition in E-business and E-government

Value, in general, refers to benefits or simply convenience a technology or service affords the end user, and value proposition is an equation of the all positive factors that interest the individual [START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF]. Value proposition identifies how the supplier fulfills the customer' s needs across different consumer roles, and further specifies the interdependence between the performance attributes of products or services and the fulfillment of needs [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF].

In the e-business domain, issues of value proposition and creation have been discussed from various business perspectives including enterprise, customer, supply chain, and markets. Value types identified by previous works include business value, customer value, product value, service value, relationship value, supply chain value, etc. Value assessment is carried out by using a set of financial and non-monetary measures. For instances, commonly mentioned value in the e-business literature include profit gains, cost savings, brand awareness, customer loyalty, etc for business companies, and time efficiency, location convenience, price deduction, customization and personalization, security and privacy protection, etc for customers.

In the e-government literature, although creating value for citizens, government agencies organizational institutions, and other stakeholders has been considered critical to the success of EG strategies and initiatives, there are only very few works comprehensively addressing value proposition, creation and assessment issues [START_REF] Badri | A Path Analytic Model and Measurement of the Business Value of e-Government: An International Perspective[END_REF][START_REF] Hossain | Impacts of Organizational Assimilation of e-Government Systems on Business Value Creation: A Structuration Theory Approach[END_REF][START_REF] Mcadam | An Inquiry into Balanced Scorecards within Best Value Implementation in UK Local Government[END_REF][START_REF] Panagiotopoulos | A Business Model Perspective for ICTs in Public Engagement[END_REF]. Among the works for developing value related framework, [START_REF] Grimsley | E-government Information Systems: Evaluation-led Design for Public Value and Client Trust[END_REF] propose an evaluative design framework for EG information system projects in which well-informedness, personal control, and influence are adopted as evaluative measures for public satisfaction and trust [START_REF] Grimsley | E-government Information Systems: Evaluation-led Design for Public Value and Client Trust[END_REF]. [START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF] presents a valuecentric EG service framework that encompasses four balanced scorecard (BSC) based dimensions for managing respectively citizen and business value, government employee and organization value, service chain, institution and administration value, as well as society and nation value [START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF]. [START_REF] Badri | A Path Analytic Model and Measurement of the Business Value of e-Government: An International Perspective[END_REF] present an EG business value model that comprises six dimensions including IT capability, search and transaction-oriented uses of EG, intelligence generation, new business development, time savings, and firm profitability [START_REF] Badri | A Path Analytic Model and Measurement of the Business Value of e-Government: An International Perspective[END_REF]. Prakash, Jaiswal, and Gulla (2009) suggest using a conceptual framework with three key dimensions including constituent service, productivity, and political consideration for assessing public value in terms of dimension associated value indicators [START_REF] Prakash | A Conceptual Framework for Measuring Public Value of Enterprise Applications[END_REF]. [START_REF] Hossain | Impacts of Organizational Assimilation of e-Government Systems on Business Value Creation: A Structuration Theory Approach[END_REF], through investigating the impact of organizational assimilation of EG systems on business value creation, operationalize the measure of EG system value in three dimensions including organizational efficiency, operational transparency, and public satisfaction [START_REF] Hossain | Impacts of Organizational Assimilation of e-Government Systems on Business Value Creation: A Structuration Theory Approach[END_REF]. [START_REF] Panagiotopoulos | A Business Model Perspective for ICTs in Public Engagement[END_REF], for analyzing and evaluating ICTs in public engagement, apply a business model perspective that consists of four dimensions including value proposition (effects), value network (actors), value architecture (resources), and value finance (costs) [START_REF] Panagiotopoulos | A Business Model Perspective for ICTs in Public Engagement[END_REF]. The value proposition is to describe the decision stages, activities, and tools, the intended benefits and effects, as well as the audience engagement.

It can be seen that since issues of value identification, proposition, assessment, and creation regarding e-business and e-government applications are largely unexplored and no consensus exists in views and structures about value, more research efforts in the direction of developing framework and metrics for defining and depicting value in both the e-business and e-government domains are strongly demanded.

Value Proposition in M-commerce and M-government

Mobile services refer to information, communication, and transaction services that are accessed and delivered via mobile communications networks. Mobile services are often classified into different categories by using different perspectives. For instances, m-services can be categorized into m-communications services, m-information services, m-transaction services, m-entertainment services, and m-community services etc by service types, into m-commerce services, and m-government services by service sectors and environments, or into m-tourism services, m-healthcare services, mlearning services, m-auction services, m-agriculture services, m-emergency services, and mobile law enforcement services etc by application domains [START_REF] Alhomod | Mobile Phone and e-Government: The Future for Dissemination of Public Services[END_REF][START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF]35,[START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF][START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF][START_REF] Monares | Mobile Computing in Urban Emergency Situations: Improving the Support to Firefighters in the Field[END_REF][START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Schubert | Mobile Communities: How Viable are Their Business Models? An Exemplary Investigation of the Leisure Industry[END_REF][START_REF] Sgriccia | Drivers of Mobile Business Models: Lessons from Four Asian Countries[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF][START_REF] Vincent | Effective Use of Mobile Communications in E-Government[END_REF]. Specific characteristics and features of m-services often mentioned include mobility, convenience, portability, adaptivity, ubiquity, personalization, localization, broadcasting, and security etc. Players involved in the mobile service chain include mobile service providers, mobile content providers, service and content aggregators, mobile device providers, mobile gateway and interface providers, and mobile network operators, etc. As mobile devices become more powerful and affordable, and more mobile services and apps are available and accessible, the goal of proposing and creating value for mobile applications becomes more achievable. In the literature, there are a plenty of previous works addressing applications and impacts of m-services in both the business and government sectors. However, there are still very few research efforts sufficiently examining the structure and process of value proposition in the mobile application domain. The lack of a unified view for value proposition of mobile services and systems is also significant.

Among research works related to mobile commerce value, Clarke III (2001) considers value proposition as a means to engender a productive m-commerce strategy, and specifies four dimensions including ubiquity, convenience, localization, and personalization to gain advantages [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF]. By defining value proposition of mobile applications as the net value of the benefits and costs associated with the adoption and adaptation of mobile applications, Nah, Siau, and Sheng (2005) adopt a value-focused thinking approach to build a means-ends objective network that depicts the causal relationships among value-converted fundamental and means objectives. Six most important fundamental objectives identified are efficiency, effectiveness, customer satisfaction, security, cost, and employee acceptance [START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF]. Through investigating industrial experts'perception of characteristics and value for mobile information systems, Hoehle and Scornavacca (2008) identify three major themes for value proposition including ubiquitous access, productivity enabler, and positive image [START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF]. Emphasizing that value proposition to customers and the balance between privacy, value, and control are keys to the acceptance of mobile technologies and services, Renegar, Michael, and Michael (2008) identify convenience, location-based services, time saving, better tracking, cost reduction, security enhancement, as well as lower prices and special promotions as the m-business value [START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF]. Focusing on defining mcommerce services and business models, [START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF] described overall value proposed to mobile customers in terms of instant access, emergency use, enhanced anytime access to new services, and increased productivity. He also points out that required functions for facilitating m-commerce services are location management, real-time delivery or service quality, transaction support, security, and wireless network reliability [START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF]. Focusing on the improvement of user-centric m-commerce services effectiveness, Germanakos et al. ( 2008) identify personalization, localization and immediacy as three dimensions for the mobile marketplace that provides services including text-based short message services (SMS), multimedia message services (MMS), and location-based services (LBS) [START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF].

As for value related works in the mobile government literature, Anttiroiko (2005) argues that the ultimate goal of introducing u-government is to generate added value from the point of view of individuals and society as a whole [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF]. He considers value as benefits related to the overall performance of public administration, such as increased productivity and effectiveness, smooth internal operations and inter-organizational interactions, better service delivery, and multiple channels for interaction. He also classifies public u-services with added value into a variety of application areas including travel and transportation, public service directories, registrations and permits, access and support, etc. [START_REF] Trimi | Emerging Trends in M-government[END_REF], based on reviewing MG initiatives in several leading countries, consider MG as value-added EG with advantages in various aspects [START_REF] Trimi | Emerging Trends in M-government[END_REF]. These advantages include improving the delivery of government information and services, providing best solutions to Internet connectivity problems and digital divide issues, offering a more cost-effective choice for national networking, helping to avoid problems of corruption and low productivity, as well as increasing government employees' efficiency and effectiveness. Most MG applications implemented are in the segments of G2C (government to citizen) and IEE (internal efficiency and effectiveness). For example, m-G2C services include government information access, text message alerts, GPS-based traffic guides, mobile tax and fee payments, and electronic ID card. M-IEE services include internal communications, in-vehicle access to crime databases for police officers, on-the-spot information processing for field inspections, tracking task assignments to workers, parking/traffic monitoring, and tax management. Ntalinai, Costopoulou, and Karetsos (2008) present a framework for introducing agricultural mobile G2B (government to business) services [START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF]. The generic agricultural m-G2B information and interaction services include news and policy, notification and alerts, forecasts and consulting, petitions and financial transactions, search engine and employment market, polls and forums, etc. The benefits for using the MG services are mobility and ubiquity, provision of location-based government services, time saving, on-time information delivery, ease of use, and improving emergency management. For addressing the acceptance issues of MG services, Aloudat and Michael (2011) [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF], and Hu et al (2011) [START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF], focus in emergency and law enforcement applications respectively. Factors considered in the former study include trust, perceived risk, perceived usefulness, perceived ease of use, visibility, perceived service quality, perceived currency, perceived accuracy, perceived responsiveness, privacy concerns, data collection concerns, and the concern of unauthorized use, while in the latter study, factors tested include efficiency gain, timely assistance, social influence, perceived usefulness, perceived ease of use, and facilitating conditions. Yan, Zhang, and Zhang (2012), provide a value analysis framework with three stages including characteristics, innovation and changes, and value for illustrating the path of MG value generation [START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Value identified include narrow digital divide, reduce management granularity, instant response, custom personal service, initiative delivery, on-spot management and service, low cost, and high efficiency. [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF], targeting on cellular citizenship, report the usage of GPS-enabled smartphones as nation-wide real-time data collection mechanisms in developing countries [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF]. The system is developed to support policy makers and planners of both the local and national levels in monitoring, assessing, and arranging human and material resources. The goal is to enhance government accountability by improving transparency in decision making and resource allocation, while increasing local planning capacity and ownership.

By reviewing research issues regarding value proposition, we summarize that previous research works address EG/MG value only partially and with inconsistent views. There is neither unified view nor complete and commonly accepted conceptual framework for illustrating the integrated structure of value proposition. It can also be noted that value proposition is a central strategic task and critical success factor in the planning and implementation of EG/MG services, value proposed to EG/MG stakeholders should be included as core elements of business models, and value associated metrics and indicators is the basis of EG/MG performance measurement. Since research in the literature addressing MG value proposition is still in its initial stage, more comprehensive studies and in-depth discussions are needed.

Integrated Framework for MG Value Proposition

To be specific, value can be considered as tangible and intangible benefits of products and/or services perceived by and exchanged between stakeholders. Then, value proposition is to propose a set of value to specific stakeholders with an implicit or explicit promise that the proposed value is to be created for and delivered to them. Many researchers consider MG as value-added EG with advantages and benefits to individuals, governments, and society [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF]. Therefore, for better understanding value proposition issues of MG services and systems, characteristics of the added value to MG services, types of delivered MG services that create value, and constituents who provide and/or use MG services to gain benefits must be realized. By doing content analysis from previous studies, as well as taking into account value chain management and business modeling concepts and methodologies, we develop an integrated framework with three dimensions including functional features, user acceptance, and user benefits, for classifying MG related value. User benefits are further classified into four constituent categories, namely, public beneficiaries, government officers and employees, participating parties of the government service chain, as well as society and nation as a whole. Figure 1 depicts the conceptual framework for value proposition in mobile government. Value dimensions and associated elements are described in the following sub-sections.

Figure 1. Conceptual framework for MG value proposition

Functional Features of MG Services

Functional features of MG services refer to the characteristics of enhanced and enabled functions that reveal added values of the m-government services. These MG functional features include mobility [START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF], ubiquity [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], portability [START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF], adaptability [START_REF] Prakash | A Conceptual Framework for Measuring Public Value of Enterprise Applications[END_REF], personalization [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF][START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF], localization/location management [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF][START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], broadcasting, accessibility [START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], multi-functional [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF], monitoring and tracking [START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF], multimedia data handling [START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF], GPS-capability [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF], and augmented reality (http://mobilegovwiki.howto.gov/Augmented+Reality). Mobility: Users can get access to mobile services independent of location and time by using mobile devices. Ubiquity: Mobile services are available 24x7 and can be accessed at anytime and anywhere with multi-channel connections. Portability: Mobile devices are easy to be carried around and can always be connected for accessing mobile services via any mobile communications networks. Adaptability: Mobile services and applications can be adapted to users' environment such as device types, network bandwidth, and locations. Localization: The capability to locate mobile users at any particular moment and to offer location-based information and services. Personalization: Mobile services and applications are tailored to meet users' needs, preferences, conditions, and environments. Broadcasting: Information can be delivered simultaneously to all mobile users within a specific geographical region. Accessibility: Anyone can easily access government information and services with the mobile devices. Multi-functional: Many different functions such as search, communication, community, multimedia data processing etc are integrated in the mobile devices. Monitoring and tracking: Data and entities can be monitored and tracked for controlling status changes. Multimedia data handling: Text, image, audio and video data can be handled using the same mobile device. GPS-capability: Geo-referred data can be collected and presented. Augmented reality: Multimedia information about the environment and its objects can be overlaid on the real world.

Functional Features

User Acceptance Levels of MG Services

User acceptance levels of MG services refer to the user perceived value of the mgovernment services and technology that reinforce their intention to use. These factors include security enhancement [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF][START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], user satisfaction [START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF], privacy protection [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF], service quality [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], transaction support [START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], system reliability. [START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF], ease of use [START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF], usefulness [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF][START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF], trust [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF], risk management [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF], visibility

User satisfaction: The ability to satisfy users with proper information and services.

Convenience: Mobile services can be accessed by users anytime and anywhere.

User Benefits of MG Services

User benefits of MG services refer to value as benefits that are to be created and delivered to users. Based on the functional features and technological capabilities of the MG services, user benefits to various constituent groups include the followings. Providing convenience in using the m-government services and systems [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF].

Providing timely assistance and transaction support to users [START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF].

Enhancing ubiquitous access to information and services [START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF].

Reducing costs in developing, operating, and using m-government services [START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF]. Attaining time saving in the m-government services process [START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF].

Facilitating user decision making process and enhancing effectiveness [START_REF] Trimi | Emerging Trends in M-government[END_REF].

Offering multiple channels for two-way user-government interactions [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF].

Offering more multimedia services for m-government users [START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF].

Offering more location-based services for m-government users [START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF].

Offering more personalized services for m-government users [START_REF] Clarke | Emerging Value Propositions for M-commerce[END_REF][START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF].

Facilitating GPS-enabled data and maps processing [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF]. Enabling citizen engagement and increasing social influence [START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF]. Attaining high process efficiency in accessing and delivering m-government services [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF][START_REF] Hu | Law Enforcement Officers'Acceptance of Advanced E-government Technology: A Survey Study of COPLINK Mobile[END_REF][START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Enhancing management effectiveness for local and central governments [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF][START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Nah | The Value of Mobile Applications: A Utility Company Study[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Enabling productivity in different sectors and levels of government agencies [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF][START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF]. Enabling better monitoring, tracking, and control of data management and services delivery processes [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF][START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF]. Attaining better awareness and positive image for government [START_REF] Hoehle | Unveiling Experts Perceptions Towards the Characteristics and Value Proposition of Mobile Information Systems[END_REF]. Facilitating special promotions of government activities [START_REF] Renegar | Privacy, Value and Control Issues in Four Mobile Business Applications[END_REF]. Facilitating on-spot and location management of data and events [START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Facilitating instant and/or real-time data collection, information access, service delivery, and transaction response [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF][START_REF] Germanakos | Improving M-Commerce Services Effectiveness with the Use of User-Centric Content Delivery[END_REF][START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Strengthening government accountability and reducing management granularity [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Improving transparency in service delivery and decision making [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF]. Increasing local government capacity in planning, operation, and control [START_REF] Berg | Cellular Citizenship: Invigorating Development Through Mobile[END_REF]. Improving emergency use and management of government resources [START_REF] Ntalinai | Mobile Government: A Challenge for Agriculture[END_REF][START_REF] Varshney | Business Models for Mobile Commerce Services: Requirements, Design, and the Future[END_REF]. Smoothing internal operations and inter-organizational interactions [START_REF] Anttiroiko | Towards Ubiquitous Government: The Case of Finland[END_REF]. Bridging/Narrowing domestic and international digital divides [START_REF] Trimi | Emerging Trends in M-government[END_REF][START_REF] Yan | The Value Analysis of Mobile Government[END_REF]. Enhancing equal digital opportunities and nation wide learning and growth [START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF].

Business Model Perspective for MG Value Proposition

In this section, value proposed to m-government users as benefits are to be classified into four constituent groups based on a business model perspective. With the BM perspective, services, constituents, value, strategic objectives, and performance indicators related to MG systems can be structurally linked and presented. By adapting a value-centric business model with the balanced scorecard perspectives provided by [START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF], the four BSC-BM perspectives for MG include public beneficiaries, government internal organization and process, government service chain, as well as society and nation [START_REF] Yu | Building a Value-Centric e-Government Service Framework Based on a Business Model Perspective[END_REF]. In the public beneficiaries perspective, the constituents include citizens, businesses, and NGOs, the value types include citizen value, business value, and NGO value, the value elements are constituent specific benefits derived from previous sections. Strategic objectives of MG services for this group are specified goals transformed from the value elements (i.e. constituent benefits) associated with this constituent group. The value-added MG services are provided in the m-G2C and m-G2B systems. The value indicators for performance measurement can then be specified accordingly. The constituent groups and associated value of the other three value-centric BSC-BM perspectives include the government officers and employees with employee value and organization value in the government internal organization and process perspective, the participating parties of the government service chain with service chain value for the entire chain and all participating parties in the government service chain perspective, as well as the society and nation as a whole with society value and nation value in the society and nation perspective. Figure 2 illustrates the BSC-BM based MG value proposition model.

Figure 2. Value proposition model based on BSC-BM perspectives

Example m-G2C services include (1) mobile information services for accessing government information about news, weather, traffic, tourism, healthcare, and jobs, (2) mobile notification and alert services for sending text message alerts and reminders about emergency conditions, tax payments, and others, (3) mobile transaction services for conducting tax and fee payments, (4) location-based services for accessing GPSenabled tour guides and road maps, (5) mobile community services for connecting people and authorities, as well as sharing knowledge and real-time information, (6) other m-services such as personalized, collaborative, and participative services.

In this paper, we propose an integrated framework with three dimensions including functional features, user acceptance, and user benefits for value proposition in mgovernment. We then use BSC based business model perspectives to classify user benefits into four constituent categories, namely, public beneficiaries, government officers and employees, participating parties of the government service chain, as well as society and nation as a whole. Value, users, systems, services, and performance indicators for each group are structurally presented. The contribution and implications of this paper are twofold. By using the proposed value framework and business model, MG planners can firstly select proper value elements from three dimensions to effectively enable m-services functions, assure user acceptance, and generate user benefits, and can secondly develop and implement MG related strategies and action plans, as well as evaluate corresponding performances based on the four BSC-BM perspectives. Furthermore, the framework is rather complete and flexible to cover previous and support future cases of MG value proposition. Directions of future research include validating the proposed MG value framework and associated indicators by conducting interviews, focus group discussions, and case studies, as well as adopting the value-centric BSC-BM for real case operation and evaluation.

 [START_REF] Aloudat | Towards the Regulation of Ubiquitous Mobile Government: A Case Studey on Location-Based Emergency Services in Australia[END_REF], currency [2], accuracy [2[, and responsiveness [2,27]. Security: The ability to ensure data and system integrity, as well as to prevent, detect, and control security attacks such as repudiation and intrusion in MG environments. Privacy: The ability to ensure that access to user accounts is restricted to authorized individuals and that the private user information is protected from unauthorized use. Trust: The ability to ensure that mobile users are well-informed, information is accurate, transactions are secure, and systems are reliable. Risk management: The ability to handle analysis, prevention, and recovery tasks regarding risk events in the MG environment. Availability: The ability to ensure that information, information accessing channels, m-service functions and systems are available when requested. Reliability: The ability to ensure that mobile services, systems as well as outcomes are consistent and accurate, and are dependably and continuously operated. Accuracy: The ability to ensure that data and information are accurate. Currency: The ability to maintain the up-to-date data and ensure timely information. Visibility: The ability to make the mobile service process visible to the users.

Responsiveness:

The ability to quickly respond to user requests and transactions. Service quality: The ability to assure high quality of delivered m-services. Ease of use: The easiness in accessing and using m-services with the provision of friendly user interfaces and mechanisms. Usefulness: The m-services are perceived useful to the users. Transaction support: The ability to support users in conducting mobile transactions.


Ansgar Mondorf
email: mondorf|wimmer@uni-koblenz.de

Maria A Wimmer

Daniel Reiser

A Framework for Interoperability Testing in Pan-European Public Service Provision

Keywords: Pan-European Public Service Provision, Interoperability Testing, Conformance Testing, Compliance Testing, Public E-Procurement

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

Introduction

Interoperability projects and initiatives often face the problem that sector specific scenarios are widely adopted by users, but the establishment of interoperability between various communities and implementations still remains cumbersome. Several authors have emphasized that greater interoperability within and across private and public sector entities could be achieved when more advanced testing methodologies and practices are used. Common guidelines for interoperability testing could foster standards adoption and could help to achieve better conformance and compliance with the underlying standards, specifications and agreements. They increase overall coherence, consistency and quality of standards and provide active support to their imple-mentation. At the same time the risk of fragmentation, duplication and conflicting testing efforts could be reduced [START_REF]CEN Workshop Agreement (CWA 16408): Testing Framework for Global eBusiness Interoperability Test Beds (GITB)[END_REF][START_REF] Dahn | Application Profiles and Tailor-Made Conformance Test Systems[END_REF].

Most authors agree that interoperability can be described upon basic characteristics which can be generally described as the ability of different ICT systems to communicate and interact with each other as well as to exchange information [START_REF] Gottschalk | E-Government Interoperability and Information Resource Integration: Frameworks for Aligned Development[END_REF][START_REF] Kosanke | ISO Standards for Interoperability: A Comparison[END_REF]. Conformance testing can be used to prove the ability of ICT system to communicate and interact together as it describes the process for verifying that an implementation of a specification fulfills its requirements both in terms of choreography of collaborations and in terms of information constraints on information elements 1 . Nevertheless there are broader definitions of interoperability which also refer to the ability of organizations to co-operate seamlessly on the basis of common processes, business rules and agreements [START_REF] Mertins | Enterprise Interoperability III[END_REF]. According to the European Interoperability Framework (EIF) interoperable specifications shall address legal, organizational, semantic and technical aspects of a business process. Although the development of European public services mostly includes the exchange of data between ICT systems, interoperability can be understood as a wider concept, encompassing for example the ability of private and public sector entities to work together towards mutually agreed goals which are beneficial to all parties involved [START_REF]European Commission: European Interoperability Framework (EIF) for European public services -Annex II -Towards interoperability for European public services[END_REF]. Taking this wider interoperability scope into account, it seems obvious that conformance testing cannot be the only means to test interoperability. In fact conformance testing can be seen as a prerequisite for interoperability testing. Interoperability testing is executed by operating implementations enforcing them to interoperate following a specific behavior [START_REF]CEN Workshop Agreement (CWA 16408): Testing Framework for Global eBusiness Interoperability Test Beds (GITB)[END_REF] and thereby addressing testing activities on legal, organizational, semantic and technical level.

Interoperability testing provides a wider scope than conformance testing as it also describes methods, processes and tools that are required by adopters to claim compliance. This not only includes the technical process of testing the conformance of document instances but also the proof that agreements are singed or legal perspectives of a system have been considered correctly during the implementation process. Interoperability testing therefore has to define a wider set of activities to ensure that systems work properly together. This paper subsequently investigates theories and related work on conformance and compliance testing in section 2. Thereby, the differences between conformance and compliance testing as well as how both fulfill a distinct need in the interoperability testing are argued. The interoperability testing framework used to support the implementation of PEPPOL building blocks through conformance and compliance testing methods is presented in section 3. The methods were aggregated to a framework to prove components against the PEPPOL specifications and agreements. While conformance testing is a well-known method in standards implementation and technical approval it does not cover all aspects required to ensure interoperability on an organizational, semantic and legal level in complex environments. The paper therefore concentrates on the use of compliance testing methods. Section 4 exemplifies the use of the framework and its testing methods in the context of the Virtual Company Dossier (VCD), a PEPPOL building block for electronic ten-dering. A number of guidelines, scenarios and underlying specifications clarify how the framework was practically implemented in the project. The conclusions in section 5 assess the benefits of a coordinated interoperability testing approach and make suggestions for further research directions.

Theories and related work

The major elements relevant to interoperability testing are conformance texting and compliance testing. In conformance testing, a specification comprises all agreements done by a community in particular the underlying standards or profiles, which represent subsets or interpretations of that specification. From an architectural perspective, agreed specifications can be described as follows:

Profiles describe specific parts of a process, where bilateral (or multilateral) communications are executed. Together they form the interfaces of that process apart from internal or back-office logic. A process consists of collaborations, which define the choreography of transactions between parties. These parties may exchange documents (e.g. a XML message) among each other. Each document instance refers to an underlying transaction data model defined in the profile. Transaction data models consist of several information elements, which may be further restricted through information constraints. An implementation of such a data model may require to be tested against the data model to proof its conformance. Conformance testing describes the process for verifying that an implementation of a specification fulfills the requirements of the profile, both in terms of choreography of collaborations and in terms of information constraints on information elements 1 .

According to Gebase et al. [START_REF] Gebase | Conformance Testing and Interoperability: A Case Study in Healthcare Data Exchange[END_REF] conformance testing is a black-box test, where the tester has no knowledge about the structure and code of the implementation. The testing environment, which aggregates the test capabilities, is named test bed. The test bed consists of a set of test assertions, which formally define the requirements or information constraints to be tested. Test assertions are intended to define constraints such as the existence or value of information elements. They may also describe cases, where a value depends on another value, a function or a code list 1 . Validators and validation artifacts such as the underlying XML-Schema, Code Lists or Schematron files are summarized within the test bed and they identify, whether a given document instance or test item complies with the defined requirements. Conformance testing may be executed through valid and invalid test items, which are sent to the test bed and thereby tested against the test assertions using the validation components of the test bed. The result is the divergence of the test item to the underlying specification or standard. Invalid test items are often used to test the validation component itself [START_REF]CEN Workshop Agreement (CWA 16408): Testing Framework for Global eBusiness Interoperability Test Beds (GITB)[END_REF][START_REF] Gebase | Conformance Testing and Interoperability: A Case Study in Healthcare Data Exchange[END_REF].

In the context of interoperability testing, conformance testing can be seen as a prerequisite for interoperability testing. Interoperability testing shall ensure that different systems work together on all levels. Interoperability testing is executed by operating implementations enforcing them to interoperate following a specific behavior [START_REF] Gebase | Conformance Testing and Interoperability: A Case Study in Healthcare Data Exchange[END_REF]. Ivezic et al. describe interoperability testing as the process for verifying that several implementations can interoperate together while conforming to one or more specifications [START_REF]CEN Workshop Agreement (CWA 16408): Testing Framework for Global eBusiness Interoperability Test Beds (GITB)[END_REF]. The authors remark that conformance testing does not guarantee interopera-bility and that in turn interoperability testing does not substitute the conformance testing. In fact, interoperability testing is usually more cost-intensive than conformance testing, since time and human efforts have to be spent in order to coordinate and set up an appropriate environment for interoperability testing. However, interoperability testing is usually more successful and less costly when the conformance of implementations has been tested first. Thus interoperability testing can largely benefit from conformance testing [START_REF]CEN Workshop Agreement (CWA 16408): Testing Framework for Global eBusiness Interoperability Test Beds (GITB)[END_REF].

The term compliance testing summarizes methods beyond conformance testing, focusing on legal and organizational aspects. All relevant methods are aggregated within the interoperability testing framework, which was conceptualized in the PEPPOL project. While the aspects of conformance were rather clear during the conceptualization, compliance testing had an unclear scope with less approaches and guidelines available. Conformance testing deals with the technical and syntactic interoperability on established standards such as XML, while covering certain semantic aspects at the same time (e.g. multilingual code list values). Thus for semantic interoperability there are some concepts and methods available, but for legal and organizational interoperability, it is by far less obvious how a standardized concept and method could look like for compliance testing, and who could develop and establish appropriate standards [START_REF] Kubicek | Three dimensions of organizational interoperability. Insights from recent studies for improving interoperability frameworks[END_REF]. The paper at hand contributes to clarify and structure the full scope of interoperability testing beyond the more technically-oriented conformance testing. The next section presents the framework for interoperability testing as developed in PEPPOL.

A Framework for Interoperability Testing

The framework for interoperability testing provides a structured approach of testing software distributions. It can be used to verify that implementations comply with specifications and requirements. It also ensures that systems considering legal and organizational cross-border aspects are appropriate. Figure 1 depicts the overall framework for interoperability testing, distinguishing main test groups and specific test types that define the outline of test executions.

Fig. 1. Test groups and test types of the framework for interoperability testing

Conformance Testing ensures that software components are able to generate and understand correct document instances. Compliance testing is particularly used to verify that legal, organizational and semantic aspects are correctly implemented. It thereby focusses on common denominators across all implementations such as the use and testing of central components as well as the execution of end-to-end tests between implementations and pilots. While compliance testing focuses on a domain specific range of issues relevant to a process (e.g. legal and organizational peculiarities, agreements, central service provision), conformance testing strictly focuses on the adherence to a standard. Both test groups are detailed subsequently.

Conformance Testing

The aim of conformance testing is to test whether software components are able to generate and understand correct document instances. Document instances in the PEPPOL VCD context are correct if they are valid along the aspects listed in table 1.

Value patterns

Correct values and format of specific element values, e.g. UUID: random UUID; Date: yyyy-mm-dd; Time: hh:mm:ss Figure 2 illustrates the phases of the conformance testing methodology. These steps allow a structured and organized testing of document instances.

Fig. 2. Conformance testing phases

The first phase covers the definition of validation requirements, business rules and information constraints that define the rules and constraints against which document instances are being validated. In order to prepare the application profiling phase, all relevant requirements and rules have to be formally defined through a schema profiling tool (e.g. SchemaProf2 ). Application profiles provide the technical basis for implementing the tests. The step of application profiling shall lead to a concrete set of test system configurations that can be processed by validation software. For the actual testing of document instances, each application profile has to be implemented as a test system. A Test System is a tool, which allows configuring test systems. It provides an executable file, through which the validation process can be started through a document instance of the test object. A detailed report is generated by the Test System after the test execution [START_REF] Dahn | Application Profiles and Tailor-Made Conformance Test Systems[END_REF]. The results of test runs have to be documented in a common way. Hence, test protocols need to be created for the different test executions, and these protocols have to be stored in a central place. Test case management software (e.g. pDAF 3 ) supports users to define common test cases and test tracks as well as to report and document executions and results.

Compliance Testing

In practice, the terms compliance and conformance are often conflated. Compliance testing means checking the behavior of a system at runtime to determine, if it behaves as desired. In contrast, conformance testing describes the ability to operate in the way defined by a specification or more precisely to test whether software components are able to generate and understand correct document instances. To make specifications suitable for implementation and interoperation, they often require to be amended through further agreements and interpretations, thus reflecting specific issues of countries and/or communities. In public procurement many processes are complex due to their legal nature. Standard specifications may reduce/exclude certain complexity aspects by assuming that an adopter/community will interpret the specifications (e.g. by defining code list and IDs) and manage varying practices in legislations (e.g. ing legal use of certified copies vs. scanned copies) correctly. In consequence, compliance testing has to focus on common specifications, their interpretation and agreements beyond the document and process level targeted by conformance testing. The framework for interoperability testing introduced in figure 1 therefore defines several compliance test types. Table 3 explains these elements by describing test types, the description and rationale of the test type and respective validation artifacts.

Proof of Concept, Test and

Production pilots 4Pilots with increasing complexity are used to specifically address legal, organisational, semantic and technical issues in a narrow and artificial setup. Proof of concept and test pilots are used to determine how the system behaves with real data but artificial set-up.

Pilots: Pilots are selected and complexity is raised gradually in order to convey the pilot from Proof of concept pilot (narrow set up) and test pilot (real data/artificial process) into productive pilot environment (real data/real process).

End-toend scenario testing

End-to-end scenario testing emphasises on the integration among systems, applications and pilots to test system dependencies. The focus of end-to-end testing scenarios lies on interfaces and dependencies between pilots.

Scenarios: End-to end scenarios ensure to test the fully integrated pilots together and to check that they act as a whole. Different pilots may be combined to build a scenario for end-to-end testing.

One could argue that the distinction between system testing and compliance testing is rather unclear since both of them focus on functional and non-functional aspects of a system. The distinction in PEPPOL was done on the basis of system dependencies and what systems shall have in common according to the PEPPOL specifications and agreements. This may include obligatory interfaces or a commonly agreed legal, organizational and semantic behavior of a system. Two further issues shall be denoted at this point: (1) Legal and organizational requirements underlie frequent changes, which result from modifications of national or European legislations. Legislative modifications therefore have to be closely monitored, and changes have to be implemented and tested in accordance with these modification. ( 2) Central components that are interfaced to many pilots or implementations also take a specific role. Responsibilities and liabilities for testing these central components have to be defined, since these components are typically used by all or many pilot implementations. In summary major elements of compliance testing are the adequate fulfillment of legal, organizational and semantic requirements, the smooth conversion of implementations into productive environments and the testing of pilots, systems and components in cooperation raising the complexity of the business process gradually.

Exemplifying Conformance Testing with PEPPOL VCD

The PEPPOL project addresses the development and implementation of technology standards to align business processes for electronic public procurement across Europe. PEPPOL's vision is to enable businesses to communicate electronically with any governmental institution in Europe for executing public procurements. PEPPOL has developed standards-based components and tools to support interoperable eprocurement in different stages of the value chain. The Virtual Company Dossier (VCD) is a component in the pre-awards stage (see e.g. [START_REF] Mondorf | The European VCD System: Facilitating Public Procurement Through Criteria to Evidence Mapping[END_REF]) and herewith serves as an example to demonstrate the underlying models of the ICT architecture and the approach to interoperability testing. PEPPOL has decided to adopt a generic Enterprise Interoperability Architecture (EIA) to organize the artifacts in a consistent and flexible way. In this paper, we rely on the structure proposed by the PEPPOL EIA 5 to reference relevant artifacts. The Virtual Company Dossier (VCD) has been developed to address the demand for better interoperability in electronic tendering offering a standardized document container to suppliers, which can be used to submit evidences (e.g. attestations and certifications) as part of the qualification process in public procurements [START_REF] Mondorf | The European VCD System: Facilitating Public Procurement Through Criteria to Evidence Mapping[END_REF]. Several VCD implementations had to be tested against the underlying standard specifications. With the PEPPOL VCD, we subsequently demonstrate the approach to interoperability testing in the project. All procurement solutions relevant to PEPPOL have been built on the basis of standards and tools recommended by the CEN/ISSS workshop on Business Interoperability Interfaces (CEN ISSS/WS BII). The CEN/ISSS workshop has published a set of BII (Business Interoperability Interface) profiles, each of them addressing a unique part of the public procurement process. A BII profile describes the choreography of the business process with a detailed description of the collaborations including roles and responsibilities. Each BII profile is referencing its business transactions to data models, which describe the core information entities on a semantic level. On a syntax level, these data models are bound to XML documents compliant with schemas from international standards such as UN/CEFACT XML and OASIS Universal Business Language 2.0. Thus a BII profile can be seen as a major reference for conformance testing as it aggregates the key requirements, agreements and standards of the underlying business process6,7 [START_REF] Kosanke | ISO Standards for Interoperability: A Comparison[END_REF][START_REF] Mertins | Enterprise Interoperability III[END_REF].

The principal specifications used in PEPPOL are known as PEPPOL Business Interoperability Specifications (PEPPOL BIS). PEPPOL BIS are based on the aforementioned BII profiles and they address additional legal, organizational, semantic and technical aspects of a business process in accordance with the European Interoperability Framework (EIF). A PEPPOL Business Interoperability Specification (BIS) summarizes all amendments which are done to a CEN BII profile. A PEPPOL BIS is more specific than a BII profiles because it adds usage-specific agreements of the PEPPOL community. It also provides supporting guidelines how to implement the requirements. A PEPPOL BIS therewith details certain aspects such as the legal scope of a specification. It also adds elements such as validation rules, identifiers and code lists that have been commonly defined in PEPPOL and addresses for example dependencies with central service components. Adopters that want to comply with a PEPPOL BIS have to comply with each interoperability layer. Thus conformance with PEPPOL BIS specifications is only one aspect of interoperability testing which focuses the syntactical and technical level and the capability of applications to generate valid document instances.

So far this paper has described the range and structure of interoperability tests executed in the PEPPOL project. In the following, an overview about the set of supporting artifacts, which are provided to adopters for the establishment and testing of PEPPOL compliant interfaces and products, is given. The artifacts listed below describe the relevant outputs according to the framework for interoperability testing introduced in section 3. They can be accessed via the PEPPOL EIA 8 . As discussed before, the VCD Business Interoperability Specification (BIS) summarizes all major aspects of interoperability testing considering all levels introduced by the EIF. The VCD BIS therewith refers to the following sub-artifacts, which are related to the test types defined for conformance testing in the testing framework:

• Specification and hierarchical data model of the data format of VCD and VCD Package in the form of testable XML schemas for the VCD, VCD Package and the common VCD library (based on UBL 2.0) (available in the PEPPOL EIA under ICT Architecture -> Models and Service Components).

• Specification of codes and values (incl. translations) of all VCD-related classified lists (i.e. code lists) provided as genericode files (available in the PEPPOL EIA under ICT Architecture -> Models and Service Components). • Abstract business rules and UBL bindings for the VCD and VCD Package and the definition of rules against which VCD and VCD Package instances must be valid (available in the PEPPOL EIA under Conformance and Test -> Models).

The above mentioned artifacts are aggregated into application profiles for VCDs and VCD Packages (available in the PEPPOL EIA under Conformance and test -> Models). SchemaProf, a tool for XML based application profiling has been used to aggregate and describe all modifications described above. The application profiles are used to create correlating VCD Conformance Test System which can automatically detect variations from the aforementioned artifacts. The Conformance Test Systems are generated from application profiles and allow automatic validation of VCD Containers against the rules defined in the VCD data model as well as requirements regarding codes and values and business rules (available in the PEPPOL EIA under Conformance and test -> Service Components).

Apart from the conformance testing artifacts, a number of compliance testing artifacts have been created:

• The ontology governance process is a guideline for setting duties, roles and responsibilities for governing the legal domain ontologies and keeping the central component, the European VCD system, up to date. As all VCD implementations depend upon this central service provision component it is essential that all adopters can rely on the information source. To ensure the quality of the information source a set of ontology quality assurance tools have been developed to establish a well-functioning quality assurance process (available in the PEPPOL EIA under Conformance and test -> Models and Service Components).

Discussion and concluding remarks

This paper introduced a generic framework for interoperability testing and exemplified its application through the PEPPOL VCD solution. Interoperability testing helps to overcome a major challenge of interoperability, i.e. it helps to validate that different implementations work together and are compliant with the underlying specifications and standards. Greater interoperability can be achieved through application of interoperability testing methods and practices to foster standards adoption. Common methods and practices increase the coherence, consistency and quality of standards, provide active support to their implementation and reduce the risk of fragmentation, duplication and conflicting testing efforts. In this respect, the paper has shown the different aspects of interoperability testing, separating clearly the concern, approach and goals of conformance testing and those of compliance testing. The use of conformance testing and compliance testing methods in PEPPOL helped to ensure that VCD solutions co-operate seamlessly on the basis of common processes, business rules and agreements of the project. Whereas conformance testing is a well-structured process that can potentially be executed automatically on any document instance using specifically designed test systems that aggregate all test assertions, compliance testing is a less structured challenge and requires more involvement of resources for designing and executing appropriate tests for the implementation under test. Overall, conformance testing was very helpful in PEPPOL for the technical approval of the system capabilities to generate correct outputs, whereas the compliance testing covered the aspects that arise from the complexity and the intention to use the solution in cross-border scenarios. For simple transactions or services with little legal and organizational constraints involved, conformance testing might be a sufficient method for testing interoperability. Transactions in complex environments with many legal risks, organizational dependencies and multilingual requirements require stronger control and specifically designed test techniques to assure proper implementation and reliability. Within the VCD context the goals of compliance testing were often conflated with other goals such as the maintenance of central service components, which provided decision support on the basis of national and European legislation. Within and beyond the project, it has to be ensured that central components are operated, monitored and updated in a reliable manner and compliance testing can help to establish routines for system changes. Another interesting aspect that was well conducted with compliance testing outcomes was the definition of appropriate and suitable conditions for production pilots. As the VCD solutions only support a specific part of e-tendering, the solutions depend and rely upon other e-tendering processes. In order to establish and use VCD implementations in production, pilot guidelines and scenarios where necessary that clarify the dependencies and interrelations with other transactions, carried out with other, conventional means such as e-tendering platforms, out of the PEPPOL scope.

The paper references accessible artifacts that have been created in PEPPOL to clarify the application of the framework. The artifacts support developers and testers in the process to check and prove VCD implementations against the VCD specifications and underlying standards. In case of new releases, existing implementations can be easily updated and adjusted using the guidance provided by these artifacts. In this respect the artifacts also support release management, maintenance and long-term sustainability. Furthermore adopters have a clear process to claim conformance to other network participants. These benefits show that a sophisticated framework for interoperability testing can strongly assist the process to develop and establish pan-European e-government services.

Future research is needed to elaborate and approve the aspects of interoperability testing presented in this paper with a particular focus on compliance testing. While conformance testing is a more mature technical method, which can be adopted easily by other projects, compliance testing is unclear in its appearance and definition. The division into legal, organizational and semantic compliance testing, pilots and end-toend testing scenarios is a first step to frame the overall scope of compliance testing. As the results of this paper have been developed in purpose of the PEPPOL solutions, their universality is not fully given at the moment. Further evidence is needed regarding suitability in other contexts and projects.

Table 1 .

 1 Validation aspects of VCD conformance testing

	Aspect	Description
	Document
	structure

Correctness of the structure and data elements of an XML instance as defined in the corresponding XML schema

Element cardinalities

Optional elements MAY exist, mandatory elements MUST exist. Prohibited elements will not be part of a profile XML schema. ─ 0..1 = optional, zero or one occurrence ─ 0..*= optional, zero or more occurrences ─ 1 = mandatory, one occurrence ─ 1..* = mandatory, one or more occurrences Data types String, integer, float, date, time, Boolean Value ranges ─ Length (for elements of type string) ─ Range (for elements of types integer, float, date and time) CodeLists Correct use of values as defined in CodeLists References ─ Correct file references in a document ─ Existence of VCD sub folders for economic operators defined in the VCD Package meta-data file. ─ Correct element references.

Table 2

 2 describes the different test types of conformance testing, which cover the validation aspects listed above.

Table 2 .

 2 Conformance test types

	Test type	Description	Rationale	Validation artefacts
	XML sche-	XML schema	As a minimum	XML schema files: Define the
	ma valida-	validation of	requirement of	technical structure of a docu-
	tion	document in-	validation, docu-	ment instance, including al-
		stances against	ment instances have	lowed elements, cardinalities,

Table 3 .

 3 Compliance test types

	Test	Description and Rational	Validation artefacts
	type
	Legal	Describes whether components fulfil	Document instances: Document instances
	organisa-	the agreed specified legal, organiza-	are used to validate whether they comply
	tional and	tional and semantic behaviour. Obliga-	with underlying legal, organizational and
	semantic	tory legal, organisational and semantic	semantic requirements.
	compli-	rules and logic need to be checked in	Test Cases Appropriate test cases define
	ance	order to determine whether systems	representative or exceptional behaviour in
	testing	adequately comply with underlying	certain legal, semantic and organisational
		legislation and organizational practices.	aspects (depending on what to test).

•

  To proof representative or exceptional behavior in certain aspects a set of test case definitions have been defined. Test cases can be aggregated to test-tracks thus complexity can be raised gradually. Test cases can be used to address certain legal, organizational, semantic aspects during process executions but they can also be used for a proof of concept and pilot testing (available in the PEPPOL EIA under Conformance and test -> Models).• Historical Call for Tenders are used to provide data to the test executions in order to build test pilots that rely on real data within an artificial process set-up (available in the PEPPOL EIA under Conformance and test -> Models). • A guideline for Contracting Authorities describes how to pilot the VCD in real environments including sample Call for Tender and sample VCD response. Since the VCD solution depends on other tendering processes beyond PEPPOL the full scope of scenarios is analyzed and suitable conditions to build effective VCD scenarios are identified (available in the PEPPOL EIA under Marketing -> Models).

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