A taxonomy of model-based testing approaches

Model-based testing (MBT) relies on models of a system under test and/or its environment to derive test cases for the system. This paper discusses the process of MBT and defines a taxonomy that covers the key aspects of MBT approaches. It is intended to help with understanding the characteristics, similarities and differences of those approaches, and with classifying the approach used in a particular MBT tool. To illustrate the taxonomy, a description of how three different examples of MBT tools fit into the taxonomy is provided.

How to design extended finite state machine test models in Java

This chapter is a tutorial that teaches you how to design extended finite state machine (EFSM) test models for a system that you want to test. EFSM models are more powerful and expressive than simple finite state machine (FSM) models, and are one of the most commonly used styles of models for model-based testing, especially for embedded systems. There are many languages and notations in use for writing EFSM models, but in this tutorial we write our EFSM models in the familiar Java programming language. To generate tests from these EFSM models we use ModelJUnit, which is an open-source tool that supports several stochastic test generation algorithms, and we also show how to write your own model-based testing tool. We show how EFSM models can be used for unit testing and system testing of embedded systems, and for offline testing as well as online testing.

Unbalance identification in large steam turbo-generator unit using a model-based method

Fault identification in industrial machine is a topic of major importance under engineering point of view. In fact, the possibility to identify not only the type, but also the severity and the position of a fault occurred along a shaft-line allows quick maintenance and shorten the downtime. This is really important in the power generation industry where the units are often of several tenths of meters long and where the rotors are enclosed by heavy and pressure-sealed casings. In this paper, an industrial experimental case is presented related to the identification of the unbalance on a large size steam turbine of about 1.3 GW, belonging to a nuclear power plant. The case history is analyzed by considering the vibrations measured by the condition monitoring system of the unit. A model-based method in the frequency domain, developed by the authors, is introduced in detail and it is then used to identify the position of the fault and its severity along the shaft-line. The complete model of the unit (rotor – modeled by means of finite elements, bearings – modeled by linearized damping and stiffness coefficients and foundation – modeled by means of pedestals) is analyzed and discussed before being used for the fault identification. The assessment of the actual fault was done by inspection during a scheduled maintenance and excellent correspondence was found with the identified one by means of authors’ proposed method. Finally a complete discussion is presented about the effectiveness of the method, even in presence of a not fine tuned machine model and considering only few measuring planes for the machine vibration.

Value creation and value capture fro open source software publisher : a new business model based on mutualisation

Key topics: Since the birth of the Open Source movement in the mid-80's, open source software has become more and more widespread. Amongst others, the Linux operating system, the Apache web server and the Firefox internet explorer have taken substantial market shares to their proprietary competitors. Open source software is governed by particular types of licenses. As proprietary licenses only allow the software's use in exchange for a fee, open source licenses grant users more rights like the free use, free copy, free modification and free distribution of the software, as well as free access to the source code. This new phenomenon has raised many managerial questions: organizational issues related to the system of governance that underlie such open source communities (Raymond, 1999a; Lerner and Tirole, 2002; Lee and Cole 2003; Mockus et al. 2000; Tuomi, 2000; Demil and Lecocq, 2006; O'Mahony and Ferraro, 2007;Fleming and Waguespack, 2007), collaborative innovation issues (Von Hippel, 2003; Von Krogh et al., 2003; Von Hippel and Von Krogh, 2003; Dahlander, 2005; Osterloh, 2007; David, 2008), issues related to the nature as well as the motivations of developers (Lerner and Tirole, 2002; Hertel, 2003; Dahlander and McKelvey, 2005; Jeppesen and Frederiksen, 2006), public policy and innovation issues (Jullien and Zimmermann, 2005; Lee, 2006), technological competitions issues related to standard battles between proprietary and open source software (Bonaccorsi and Rossi, 2003; Bonaccorsi et al. 2004, Economides and Katsamakas, 2005; Chen, 2007), intellectual property rights and licensing issues (Laat 2005; Lerner and Tirole, 2005; Gambardella, 2006; Determann et al., 2007). A major unresolved issue concerns open source business models and revenue capture, given that open source licenses imply no fee for users. On this topic, articles show that a commercial activity based on open source software is possible, as they describe different possible ways of doing business around open source (Raymond, 1999; Dahlander, 2004; Daffara, 2007; Bonaccorsi and Merito, 2007). These studies usually look at open source-based companies. Open source-based companies encompass a wide range of firms with different categories of activities: providers of packaged open source solutions, IT Services&Software Engineering firms and open source software publishers. However, business models implications are different for each of these categories: providers of packaged solutions and IT Services&Software Engineering firms' activities are based on software developed outside their boundaries, whereas commercial software publishers sponsor the development of the open source software. This paper focuses on open source software publishers' business models as this issue is even more crucial for this category of firms which take the risk of investing in the development of the software. Literature at last identifies and depicts only two generic types of business models for open source software publishers: the business models of ''bundling'' (Pal and Madanmohan, 2002; Dahlander 2004) and the dual licensing business models (Välimäki, 2003; Comino and Manenti, 2007). Nevertheless, these business models are not applicable in all circumstances. Methodology: The objectives of this paper are: (1) to explore in which contexts the two generic business models described in literature can be implemented successfully and (2) to depict an additional business model for open source software publishers which can be used in a different context. To do so, this paper draws upon an explorative case study of IdealX, a French open source security software publisher. This case study consists in a series of 3 interviews conducted between February 2005 and April 2006 with the co-founder and the business manager. It aims at depicting the process of IdealX's search for the appropriate business model between its creation in 2000 and 2006. This software publisher has tried both generic types of open source software publishers' business models before designing its own. Consequently, through IdealX's trials and errors, I investigate the conditions under which such generic business models can be effective. Moreover, this study describes the business model finally designed and adopted by IdealX: an additional open source software publisher's business model based on the principle of ''mutualisation'', which is applicable in a different context. Results and implications: Finally, this article contributes to ongoing empirical work within entrepreneurship and strategic management on open source software publishers' business models: it provides the characteristics of three generic business models (the business model of bundling, the dual licensing business model and the business model of mutualisation) as well as conditions under which they can be successfully implemented (regarding the type of product developed and the competencies of the firm). This paper also goes further into the traditional concept of business model used by scholars in the open source related literature. In this article, a business model is not only considered as a way of generating incomes (''revenue model'' (Amit and Zott, 2001)), but rather as the necessary conjunction of value creation and value capture, according to the recent literature about business models (Amit and Zott, 2001; Chresbrough and Rosenblum, 2002; Teece, 2007). Consequently, this paper analyses the business models from these two components' point of view.

Fluid-structure interaction analysis by coupled FE-SPH model based on a novel searching algorithm

Fluid–Structure Interaction (FSI) problem is significant in science and engineering, which leads to challenges for computational mechanics. The coupled model of Finite Element and Smoothed Particle Hydrodynamics (FE-SPH) is a robust technique for simulation of FSI problems. However, two important steps of neighbor searching and contact searching in the coupled FE-SPH model are extremely time-consuming. Point-In-Box (PIB) searching algorithm has been developed by Swegle to improve the efficiency of searching. However, it has a shortcoming that efficiency of searching can be significantly affected by the distribution of points (nodes in FEM and particles in SPH). In this paper, in order to improve the efficiency of searching, a novel Striped-PIB (S-PIB) searching algorithm is proposed to overcome the shortcoming of PIB algorithm that caused by points distribution, and the two time-consuming steps of neighbor searching and contact searching are integrated into one searching step. The accuracy and efficiency of the newly developed searching algorithm is studied on by efficiency test and FSI problems. It has been found that the newly developed model can significantly improve the computational efficiency and it is believed to be a powerful tool for the FSI analysis.

Adoption of accountable-eHealth systems by future healthcare professionals: An empirical research model based on the Australian context

This paper provides a first look at the acceptance of Accountable-eHealth systems, a new genre of eHealth systems, designed to manage information privacy concerns that hinder the proliferation of eHealth. The underlying concept of AeH systems is appropriate use of information through after-the-fact accountability for intentional misuse of information by healthcare professionals. An online questionnaire survey was utilised for data collection from three educational institutions in Queensland, Australia. A total of 23 hypothesis relating to 9 constructs were tested using a structural equation modelling technique. A total of 334 valid responses were received. The cohort consisted of medical, nursing and other health related students studying at various levels in both undergraduate and postgraduate courses. The hypothesis testing disproved 7 hypotheses. The empirical research model developed was capable of predicting 47.3% of healthcare professionals’ perceived intention to use AeH systems. A validation of the model with a wider survey cohort would be useful to confirm the current findings.

Model-based analysis and optimization of bioreactor for hematopoietic stem cell cultivation

One of the problems to be solved in attaining the full potentials of hematopoietic stem cell (HSC) applications is the limited availability of the cells. Growing HSCs in a bioreactor offers an alternative solution to this problem. Besides, it also offers the advantages of eliminating labour intensive process as well as the possible contamination involved in the periodic nutrient replenishments in the traditional T-flask stem cell cultivation. In spite of this, the optimization of HSC cultivation in a bioreactor has been barely explored. This manuscript discusses the development of a mathematical model to describe the dynamics in nutrient distribution and cell concentration of an ex vivo HSC cultivation in a microchannel perfusion bioreactor. The model was further used to optimize the cultivation by proposing three alternative feeding strategies in order to prevent the occurrence of nutrient limitation in the bioreactor. The evaluation of these strategies, the periodic step change increase in the inlet oxygen concentration, the periodic step change increase in the media inflow, and the feedback control of media inflow, shows that these strategies can successfully improve the cell yield of the bioreactor. In general, the developed model is useful for the design and optimization of bioreactor operation.

An insight into the adoption of accountable-eHealth systems: n empirical research model based on the Australian context

This paper provides a first look at the acceptance of Accountable-eHealth (AeH) systems–a new genre of eHealth systems designed to manage information privacy concerns that hinder the proliferation of eHealth. The underlying concept of AeH systems is appropriate use of information through after-the-fact accountability for intentional misuse of information by healthcare professionals. An online questionnaire survey was utilised for data collection from three educational institutions in Queensland, Australia. A total of 23 hypotheses relating to 9 constructs were tested using a structural equation modelling technique. The moderation effects on the hypotheses were also tested based on six moderation factors to understand their role on the designed research model. A total of 334 valid responses were received. The cohort consisted of medical, nursing and other health related students studying at various levels in both undergraduate and postgraduate courses. Hypothesis testing provided sufficient data to accept 7 hypotheses. The empirical research model developed was capable of predicting 47.3% of healthcare professionals’ perceived intention to use AeH systems. All six moderation factors showed significant influence on the research model. A validation of this model with a wider survey cohort is recommended as a future study.