M.Com. (Industrial Psychology) / Please refer to full text to view abstract

There is a potential as well as a growing interest amongst researchers to utilise simulation in optimising maintenance systems. The state of the art in simulation-based optimisation of maintenance was established by systematically classifying the published literature and outlining main trends in modelling and optimising maintenance systems. In general, approaches to optimise maintenance varied significantly in the literature. Overall, these studies highlight the need for a framework that unifies the approach to optimising maintenance systems. Framework requirements were established through two main sources of published research. Surveys on maintenance simulation optimisation were examined to document comments on the approaches authors follow while optimising maintenance systems. In addition, advanced and future maintenance strategies were documented to ensure it can be accommodated in the proposed framework. The proposed framework was developed using a standard flowchart tool due to its familiarity and ability to depict decision structures clearly. It provides a systematic methodology that details the steps required to connect the simulation model to an optimisation engine. Not only it provides guidance in terms of formulating the optimal problem for the maintenance system at hand but it also provides support and assistance in defining the optimisation scope and investigating applicable maintenance strategies. Additionally, it considers current issues relating to maintenance systems both in research and in practice such as uncertainty, complexity and multi-objective optimisation. The proposed framework cannot be applied using existing approaches for modelling maintenance. Existing modelling approaches using simulation have a number of limitations: The maintenance system is modelled separately from other inter-related systems such as production and spare parts logistics. In addition, these approaches are used to model one maintenance strategy only. A novel approach for modelling maintenance using Discrete Event Simulation is proposed. The proposed approach enables the modelling of interactions amongst various maintenance strategies and their effects on the assets in non-identical multi-unit systems. Using the proposed framework and modelling approach, simulation-based optimisation was conducted on an academic case and two industrial cases that are varied in terms of sector, size, number of manufacturing processes and level of maintenance documentation. Following the structured framework enabled discussing and selecting the suitable optimisation scope and applicable maintenance strategies as well as formulating a customised optimal problem for each case. The results of the study suggest that over-looking the optimisation of maintenance strategies may lead to sub-optimal solutions. In addition, this research provides insights for non-conflicting objectives in maintenance systems.

There is a potential as well as a growing interest amongst researchers to utilise simulation in optimising maintenance systems. The state of the art in simulation-based optimisation of maintenance was established by systematically classifying the published literature and outlining main trends in modelling and optimising maintenance systems. In general, approaches to optimise maintenance varied significantly in the literature. Overall, these studies highlight the need for a framework that unifies the approach to optimising maintenance systems. Framework requirements were established through two main sources of published research. Surveys on maintenance simulation optimisation were examined to document comments on the approaches authors follow while optimising maintenance systems. In addition, advanced and future maintenance strategies were documented to ensure it can be accommodated in the proposed framework. The proposed framework was developed using a standard flowchart tool due to its familiarity and ability to depict decision structures clearly. It provides a systematic methodology that details the steps required to connect the simulation model to an optimisation engine. Not only it provides guidance in terms of formulating the optimal problem for the maintenance system at hand but it also provides support and assistance in defining the optimisation scope and investigating applicable maintenance strategies. Additionally, it considers current issues relating to maintenance systems both in research and in practice such as uncertainty, complexity and multi-objective optimisation. The proposed framework cannot be applied using existing approaches for modelling maintenance. Existing modelling approaches using simulation have a number of limitations: The maintenance system is modelled separately from other inter-related systems such as production and spare parts logistics. In addition, these approaches are used to model one maintenance strategy only. A novel approach for modelling maintenance using Discrete Event Simulation is proposed. The proposed approach enables the modelling of interactions amongst various maintenance strategies and their effects on the assets in non-identical multi-unit systems. Using the proposed framework and modelling approach, simulation-based optimisation was conducted on an academic case and two industrial cases that are varied in terms of sector, size, number of manufacturing processes and level of maintenance documentation. Following the structured framework enabled discussing and selecting the suitable optimisation scope and applicable maintenance strategies as well as formulating a customised optimal problem for each case. The results of the study suggest that over-looking the optimisation of maintenance strategies may lead to sub-optimal solutions. In addition, this research provides insights for non-conflicting objectives in maintenance systems.

<p>This thesis presents empirical research in the field of software development with a focus on handling semantic aspects. There is a general lack of empirical data in the field of software development. This makes it difficult for industry to choose an appropriate method for their particular needs. The lack of empirical data also makes it difficult to convey academic results to the industrial world.</p><p>This thesis tries to remedy this problem by presenting a number of empirical evaluations that have been conducted to evaluate some common approaches in the field of semantics handling. The evaluations have produced some interesting results, but their main contribution is the addition to the body of knowledge on how to perform empirical evaluations in software development. The evaluations presented in this thesis include a between-groups controlled experiment, industrial case studies and a full factorial design controlled experiment. The factorial design seems like the most promising approach to use when the number of factors that need to be controlled is high and the number of available test subjects is low. A factorial design has the power to evaluate more than one factor at a time and hence to gauge the effects from different factors on the output.</p><p>Another contribution of the thesis is the development of a method for handling semantic aspects in an industrial setting. A background investigation performed concludes that there seems to be a gap between what academia proposes and how industry handles semantics in the development process. The proposed method aims at bridging this gap. It is based on academic results but has reduced formalism to better suit industrial needs. The method is applicable in an industrial setting without interfering too much with the normal way of working, yet providing important benefits. This method is evaluated in the empirical studies along with other methods for handling semantics. In the area of semantic handling, further contributions of the thesis include a taxonomy for semantic handling methods as well as an improved understanding of the relation between semantic errors and the concept of contracts as a means of avoiding and handling these errors.</p>

This thesis presents empirical research in the field of software development with a focus on handling semantic aspects. There is a general lack of empirical data in the field of software development. This makes it difficult for industry to choose an appropriate method for their particular needs. The lack of empirical data also makes it difficult to convey academic results to the industrial world. This thesis tries to remedy this problem by presenting a number of empirical evaluations that have been conducted to evaluate some common approaches in the field of semantics handling. The evaluations have produced some interesting results, but their main contribution is the addition to the body of knowledge on how to perform empirical evaluations in software development. The evaluations presented in this thesis include a between-groups controlled experiment, industrial case studies and a full factorial design controlled experiment. The factorial design seems like the most promising approach to use when the number of factors that need to be controlled is high and the number of available test subjects is low. A factorial design has the power to evaluate more than one factor at a time and hence to gauge the effects from different factors on the output. Another contribution of the thesis is the development of a method for handling semantic aspects in an industrial setting. A background investigation performed concludes that there seems to be a gap between what academia proposes and how industry handles semantics in the development process. The proposed method aims at bridging this gap. It is based on academic results but has reduced formalism to better suit industrial needs. The method is applicable in an industrial setting without interfering too much with the normal way of working, yet providing important benefits. This method is evaluated in the empirical studies along with other methods for handling semantics. In the area of semantic handling, further contributions of the thesis include a taxonomy for semantic handling methods as well as an improved understanding of the relation between semantic errors and the concept of contracts as a means of avoiding and handling these errors.

GUI testing is expensive to perform manually. Software systems involving a heterogeneous set of components exclude the applicability of specific GUI testing techniques. Visual GUI Testing (VGT) is a test automation technique that combines image recognition with scripts. It applies to almost any GUI driven application. VGT is proven to be cost-effective in comparison with manual testing. Still, it is expensive to maintain. This study investigates if test script design by following specific guidelines positively affects maintenance costs. A case study was conducted to identify best practices for VGT w.r.t. maintenance time. Four VGT versions were developed for each manual test case. These consisted of two design versions, with/without guidelines, for the two VGT-tools EyeAutomate and Sikuli. Data was collected using time measurements, observations, and interviews. Results highlighted differences in initial development time and maintenance time between the two design versions. In total, 44 observations were collected. 17 were related to the design versions, 17 to the VGT-tools, and 10 to VGT in general, initial development, and the system under test. The interviews collected the perceptions of VGT in general, maintenance of the different VGT versions, and guidelines. In conclusion, the combination of the guidelines did not have a positive effect on maintenance in terms of costs and experience. However, some of the individual guidelines did. A rationale why the guidelines did not give the desired result was identified. Future research is necessary to investigate other combinations of guidelines, such as those identified as beneficial.

Aspect oriented programming (AOP) introduces new and powerful modularization constructs. The aspect module is used to encapsulate crosscutting concerns, which otherwise would remain tangled and scattered. The idea of encapsulating crosscutting concerns rapidly expanded to earlier phases in the development cycle, including requirement analysis (aspect oriented requirement engineering, AORE) and design (aspect oriented modeling, AOM). The overall application of aspect orientation concepts is known as aspect oriented software development (AOSD). AOP is not yet a mainstream practice. Particularly AOSD is still in its early stages. This is reflected in the lack of reports of full development cycles using aspect oriented approaches, especially using industrial case studies. Furthermore, the power of aspects comes at the price of new challenges, one of them is that systems built using aspects are more difficult to understand. The crosscutting nature of aspects allows them to alter the behavior of many other modules. As a result, aspects may interact in unintended and unanticipated ways. This problem is known as aspect interactions. In this work we deal with the aspect interaction problem in the context of an industrial domain: slots machines. We perform a complete development cycle of the slot machine software. This is, to the best of our knowledge, the first complete industrial case of study of aspect orientation. Through this experience we discovered the limitations with regard to aspect interactions, of some emblematic aspect oriented approaches for requirement engineering, design and implementation. The contribution of this work is threefold. Firstly, we contribute with the evaluation and extensions to some of AORE and AOM approaches, in order to provide explicit support for aspect interactions in requirement analysis and design phases. We also evaluate the implementation of interactions using a static and a dynamic AOP language, and propose an AspectJ extension that copes with aspect interactions. Secondly, this work is the first report of a complete aspect oriented development cycle of an industrial case study. Thirdly, this work provides a complex case study that presents several business logic crosscutting concerns, which in turn exhibit numerous aspect interactions, that serves as a challenging test bed for upcoming AOSD approaches.

Em projetos de desenvolvimento a qualidade do produto de software é fundamental para o seu sucesso. Uma das etapas que busca garantir a qualidade do produto final é a validação, verificação e teste (VV&T). O teste é uma das atividades chave de VV&T realizada para garantir a qualidade. Técnicas de teste foram desenvolvidas para verificar e validar tanto requisitos funcionais como não funcionais. Além disso, essas técnicas são aplicadas nas organizações por meio de estratégias que definem os tipos de teste que serão realizados, a ordem de realização, a sua automatização e a frequência de ocorrência. Uma questão importante é verificar como essa atividade é realizada na indústria de software, como essas técnicas são utilizadas e a sua adoção em organizações desenvolvedoras de software. Este trabalho apresenta uma pesquisa qualitativa da atividade de teste. Ela utilizou a técnica teoria fundamentada aplicada em cinco empresas desenvolvedoras de software para estabelecer uma teoria da atividade de teste. Foram realizadas entrevistas com gestores de teste das empresas e, a partir dessas entrevistas, foi desenvolvido uma teoria sobre a organização da atividade de teste. Nesta teoria, observou-se que a estrutura organizacional direciona a escolha das técnicas e ferramentas, bem como o tipo do sistema; o prazo e orçamento condicionam a utilização de técnicas de automatização / In development projects the quality of the software product is critical to its success. One of the steps that enforces the quality of the final product is validation, verification and testing (VV&T). Testing is one of the key VV&T activities to ensure quality. Testing techniques were developed to verify and validate both functional and non-functional requirements. In addition, these techniques are applied in organizations using strategies that define the testing techniques that will be performed, the order of application, their automation and the frequency of occurrence. An important issue is to verify how testing is carried out in the software industry, how these techniques are used and their adoption in industrial settings. This work presents a qualitative research of the testing activity. It used the grounded theory technique applied in five software development organizations to establish a model of the testing activity. Interviews were conducted with testing managers and, from these interviews, an organizational theory of the testing activity was developed. In this theory, it was observed that the organizational structure directs the choice of techniques and tools, as well as the type of the system; project schedule and budget limit the use of automation techniques

Contexte: La société IP Leanware est une start-up en pleine expansion. Créée en 2008, son C.A. a quadruplé en 4 ans et elle a implantée deux filiales (Brésil et Etats-Unis). Depuis, sa croissance est à deux chiffres (2015). Elle optimise la performance d’entreprises industrielles par un logiciel (BrainCube) qui identifie les conditions de sur-performance. La thèse, réalisée en CIFRE au sein du service R&D dirigé par Sylvain Rubat du Mérac, se situe à l’interface du contrôle de gestion, de la gestion de production et des systèmes d’information. Objectif : BrainCube gère des données descriptives massives des flux des processus de ses clients. Son moteur d’analyse identifie les situations de sur-performance et les diffusent en temps réel par des interfaces tactiles. BrainCube couple deux flux : informationnels et physiques. La mission est d'intégrer la variable économique. Une étude de la littérature montre qu’une évaluation simultanée en temps réel des flux physiques, informationnels et financiers, couplée à une amélioration continue des processus de production, n'est pas réalisée. Résultat : Une revue de la littérature étudie les pratiques et les méthodes du contrôle de gestion pour proposer une méthode temps réel adaptée aux spécificités de BrainCube. L'étude de cas, basée sur une recherche-ingénierique, propose une méthodologie de modélisation générique de la variable économique. Des modèles génériques décisionnels paramétrables sont proposés. Ils doivent faciliter l'usage d'une information temps réel à forte granularité. Les apports, limites et perspectives mettent en relief l'intérêt des travaux pour l'entreprise et les sciences de gestion. / Context: IP Leanware is a growing start-up. Created in 2008, its consolidated sales has quadrupled in 4 years and established two subsidiaries (Brazil and the United States). Since then, its growth has been two digits (2015). It optimizes the performance of industrial companies with software (BrainCube) that identifies overperformance conditions. The thesis, carried out in CIFRE within the R&D service led by Sylvain Rubat du Mérac, is located at the interface of management control, production management and information systems.Aim: BrainCube manages massive descriptive data of its customers' process flows. Its analysis engine identifies overperformance situations and broadcasts them in real time through tactile interfaces. BrainCube couples two flows: informational and physical. The mission is to integrate the economic variable. A literature study shows that simultaneous real-time evaluation of physical, informational and financial flows coupled with continuous improvement of production processes is not realized.Result: A literature review examines the practices and methods of management control to propose a real-time method adapted to the specificities of BrainCube. The case study, based on an engineering-research, proposes a generic modeling methodology of the economic variable. Configurable generic decision models are proposed. They must facilitate the use of real time information with high granularity. The contributions, limits and perspectives highlight the interest of works for the company and the management sciences.

Em projetos de desenvolvimento a qualidade do produto de software é fundamental para o seu sucesso. Uma das etapas que busca garantir a qualidade do produto final é a validação, verificação e teste (VV&T). O teste é uma das atividades chave de VV&T realizada para garantir a qualidade. Técnicas de teste foram desenvolvidas para verificar e validar tanto requisitos funcionais como não funcionais. Além disso, essas técnicas são aplicadas nas organizações por meio de estratégias que definem os tipos de teste que serão realizados, a ordem de realização, a sua automatização e a frequência de ocorrência. Uma questão importante é verificar como essa atividade é realizada na indústria de software, como essas técnicas são utilizadas e a sua adoção em organizações desenvolvedoras de software. Este trabalho apresenta uma pesquisa qualitativa da atividade de teste. Ela utilizou a técnica teoria fundamentada aplicada em cinco empresas desenvolvedoras de software para estabelecer uma teoria da atividade de teste. Foram realizadas entrevistas com gestores de teste das empresas e, a partir dessas entrevistas, foi desenvolvido uma teoria sobre a organização da atividade de teste. Nesta teoria, observou-se que a estrutura organizacional direciona a escolha das técnicas e ferramentas, bem como o tipo do sistema; o prazo e orçamento condicionam a utilização de técnicas de automatização / In development projects the quality of the software product is critical to its success. One of the steps that enforces the quality of the final product is validation, verification and testing (VV&T). Testing is one of the key VV&T activities to ensure quality. Testing techniques were developed to verify and validate both functional and non-functional requirements. In addition, these techniques are applied in organizations using strategies that define the testing techniques that will be performed, the order of application, their automation and the frequency of occurrence. An important issue is to verify how testing is carried out in the software industry, how these techniques are used and their adoption in industrial settings. This work presents a qualitative research of the testing activity. It used the grounded theory technique applied in five software development organizations to establish a model of the testing activity. Interviews were conducted with testing managers and, from these interviews, an organizational theory of the testing activity was developed. In this theory, it was observed that the organizational structure directs the choice of techniques and tools, as well as the type of the system; project schedule and budget limit the use of automation techniques