| 1. |
- Mellegård, Niklas, 1971, et al.
(författare)
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A Domain Specific Modelling Language for Specifying and Visualizing Requirements
- 2009
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Ingår i: DE@CAiSE 2009. - 1613-0073. ; 457
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Konferensbidrag (refereegranskat)abstract
- Requirements can cause substantial problems in large software projects if not handled correctly and efficiently. The problems of missing requirements or incorrect de-scoping of projects are virtually the most prominent ones. Combining graphical representation of requirements and organizing these requirements in several abstraction levels was identified as one of the potential solutions to such issues in our research project conducted with one of major automotive companies in Sweden. The objective of the research reported in this paper is to improve requirements engineering activities by using a graphical modelling language for managing requirements based on Requirement Abstraction Model (RAM). We evaluated our results via a pilot controlled experiment and the results show a statistically significant improvement in the time required to assess the impact of changes by 37% with the same accuracy.
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| 2. |
- Mellegård, Niklas, 1971, et al.
(författare)
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A light-weight defect classification scheme for embedded automotive software and its initial evaluation
- 2012
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Ingår i: International Symposium on Software Reliability Engineering (ISSRE). - 1071-9458. - 9780769548883 ; , s. 261-270
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Konferensbidrag (refereegranskat)abstract
- Objective: Defect classification is an essential part of software development process models as a means of early identification of patterns in defect inflow profiles. Such classification, however, may often be a tedious task requiring analysis work in addition to what is necessary to resolve the issue. To increase classification efficiency, adapted schemes are needed. In this paper a light-weight defect classification scheme adapted for minimal process footprint – in terms of learning and classification effort – is proposed and initially evaluated. Method: A case study was conducted at Volvo Car Corporation to adapt the IEEE Std. 1044 for automotive embedded software. An initial evaluation was conducted by applying the adapted scheme to defects from an existing software product with industry professionals as subjects. Results: The results showed that the classification scheme was quick to learn and understand – required classification time stabilized around 5-10 minutes already after practicing on 3-5 defects. The results also showed that the patterns in the classified defects were interesting for the professionals, although more data was needed to provide statistics. Conclusions: We conclude that the adapted classification scheme captures what is currently tacit knowledge and has the potential of revealing patterns in the defects detected in different project phases. Furthermore, we were, in the initial evaluation, able to contribute with new information about the development process. As a result we are currently in the process of incorporating the classification scheme into the company’s defect reporting system.
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| 3. |
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| 4. |
- Mellegård, Niklas, 1971, et al.
(författare)
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Characterizing Model Usage in Embedded Software Engineering: A Case Study
- 2010
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Ingår i: 8th Nordic Workshop on Model Driven Software Engineering (NW-MoDE). - New York, NY, USA : ACM. ; , s. 245-252
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Konferensbidrag (refereegranskat)abstract
- During development of complex products, such as automotive software, models – formal and informal – are used throughout the development process by different roles and for different purposes – as requirement, as implementation or as documentation. This paper reports results from a case-study of the development of embedded software at a Swedish vehicle manufacturer. We investigated use of models from high-level product planning to low-level requirements specifications for software components. Furthermore, we investigated the distribution of effort among the models, requirements and other artefacts. The goal was to explore the spectrum of modelling techniques, methods and languages used and to establish a baseline for comparison with the state-of-the-art and other companies. The results show that there exist at least 8 different modelling notations. Moreover, we found that the majority of effort was spent on behaviour models, while static models – such as high-level design and requirements – were considered most important.
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| 5. |
- Mellegård, Niklas, 1971, et al.
(författare)
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Distribution of Effort Among Software Development Artefacts: An Initial Case Study
- 2010
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Ingår i: Lecture Notes in Business Information Processing. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1865-1356 .- 1865-1348. - 9783642130502 ; 50, s. 234-246
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Konferensbidrag (refereegranskat)abstract
- Model-driven development aims at increasing productivity by raising the abstraction level of software specifications and introducing automated transformations for replacing lower level specifications. To assess benefits of replacing a legacy development process with a model-driven approach, one needs to establish a baseline of the current process with respect to the effort invested in the development artefacts. In this paper we report on an initial case study in which we investigate the main artefacts in the analysis and design phase with respect to required effort and perceived importance. We studied a non-model driven development of software based automotive functionality and our initial results show that a few artefacts receive the majority of effort, and that the artefacts that receive the most effort are not the most important ones. The initial results indicate that the distribution of effort between models and other artefacts is similar to that of model-driven projects in spite of the project being perceived and characterized as code-centric.
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| 6. |
- Mellegård, Niklas, 1971, et al.
(författare)
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Impact of Introducing Domain-Specific Modelling in Software Maintenance: An Industrial Case Study
- 2016
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Ingår i: Ieee Transactions on Software Engineering. - : Institute of Electrical and Electronics Engineers (IEEE). - 0098-5589 .- 1939-3520. ; 42:3, s. 248-263
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Tidskriftsartikel (refereegranskat)abstract
- Domain-specific modelling (DSM) is a modern software development technology that aims at enhancing productivity. One of the claimed advantages of DSM is increased maintainability of software. However, current empirical evidence supporting this claim is lacking. In this paper, we contribute evidence from a case study conducted at a software development company. We study how the introduction of DSM affected the maintenance of a legacy system. We collected data about the maintenance phase of a system that was initially developed using manual programming, but which was gradually replaced by DSM development. We performed statistical analyses of the relation between the use of DSM and the time needed to resolve defects, the defect density, and the phase in which defects were detected. The results show that after introducing DSM the defect density is lower, that defects are found earlier, but resolving defects takes longer. Other observed benefits are that the number of developers and the number of person-hours needed for maintaining the system decreased, and the portability to new platforms increased. Our findings are useful for organizations that consider introducing DSM and would like to know which benefits can be realized in software maintenance.
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| 7. |
- Mellegård, Niklas, 1971
(författare)
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Improving Defect Management in Automotive Software Development, LiDeC---A Light-weight Defect Classification Scheme
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Classification of software defects is a means to provide defect reports with a shared and well-defined structure. Quantitative analyses of the classification data facilitated by the shared structure are useful to industry practitioners and academic researchers. For practitioners, especially in large, complex or dynamic organizations, analyses can provide valuable information that characterize the development process, assist in identifying improvement opportunities, and provide one basis for predictions (e.g. product quality and resource needs). For researchers, classification data can facilitate evaluating effects of improved practices (e.g. new methods and tools) by analysing classified defect data before and after applying the hypothesized improved practice.Although recognized as a promising approach, there has to date been limited research reported on defect classification schemes—specifically on the efficiency of their application in industry, and on the reliability of the classification data. Efficient classification is desirable as it minimizes the time required to classify defects. Reliability of the classification data is important as it directly affects the reliability of conclusions drawn from analyses of the data. In this thesis, a defect classification scheme based on and compliant to the standard classification for software anomalies (IEEE Std. 1044) is described and evaluated. The classification scheme, LiDeC (Light-weight Defect Classification Scheme), was adapted to and applied in the development of automotive safety software.Through case studies and an experiment, LiDeC was evaluated with respect to its industrial applicability, efficiency and reliability. The results show that analyses of classification data can provide new and useful information about the effectiveness of current development practices. Applying a classification scheme adapted to the target organization results in analyses that are more directly relevant to that organization. Academic experimentation showed that classification schemes are easy to learn and to apply—even when lacking domain specific knowledge, the experiment subjects were able to arrive at rational classifications.The main contributions of the thesis include: the description of an adaptation of the standard classification scheme to a specific organization while maintaining standard compliance; an initial industrial evaluation of the applicability of the adapted classification scheme; a description of a methodology for comprehensively evaluating defect classification schemes; and finally, an investigation of current state-of-the-art with respect to defect classification, and a proposed roadmap for future research.
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| 8. |
- Mellegård, Niklas, 1971, et al.
(författare)
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Improving Efficiency of Change Impact Assessment Using Graphical Requirement Specifications: An Experiment
- 2010
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Ingår i: Lecture Notes in Computer Science. 11th International Conference on Product-Focused Software Process Improvement, PROFES 2010, Limerick, 21-23 June 2010. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0302-9743 .- 1611-3349. - 9783642137914 ; 6156, s. 336-350
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Konferensbidrag (refereegranskat)abstract
- Objective: Graphical requirements representation is often considered needed to advance model-driven development. Dedicated modelling languages include formalisms for graphically representing requirements, and together with new methods for structuring requirements, graphical modelling promises improvements such as more efficient change management. This paper examines whether the use of a graphical notation of a requirements affects the task of assessing the impact of a proposed change to a requirements specification. Method: The efficiency of using a graphical requirements representation was examined through an experiment – using 18 student subjects. Time, perceived confidence and accuracy were measured as dependent variables. Result: The results showed that using a graphical representation decreased the time required and increased the perceived confidence, but the accuracy decreased. However, the statistical analysis of the results showed that only the difference in time was significant. Furthermore, there was a large difference in variance within the dependent variables between the groups.
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| 9. |
- Mellegård, Niklas, 1971
(författare)
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Method and Tool Support for Automotive Software Engineering
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modelling is an essential activity in all engineering disciplines, and automotive software engineering is no exception. Model-driven software engineering – which has been shown with extensive evidence to improve efficiency and effectiveness of software development – acknowledges the centrality of models and advocates the use of models as primary development artefacts; it is in the models that work should be done, and other development artefacts – such as requirement specifications, documentation and source code – should be generated from the models.Introducing a model-driven development approach in a previously non model-driven process, however, presents specific challenges to the development organization; there is, furthermore, no consensus in the current state of research how to best make such a transition. In the automotive domain, where software engineering is only one of several engineering disciplines involved in development of the car, best practices for transitioning to a model-driven approach are yet more unclear.In addition, the overarching development paradigm in the automotive domain is often document-centric – i.e. it is in textual documents that development information is officially disseminated in the development organization. Nevertheless, software models have been found to play a central role within projects in the organization.In this thesis, the main research question is: How can model-driven development methods improve the development of automotive software? The approach taken is to acknowledge that the overarching development paradigm will remain unchanged, and to examine how – in the current development practice – software models are used within individual projects. Moreover, the thesis examines how these models relate to the documents in which development information is disseminated in the organization-wide development process.Using triangulation of empirical and theoretical research methods, the results in the thesis show that there can be fundamental differences between an organization-wide process and how that process is implemented within individual project; the results also identify issues related to this fact. The results, furthermore, provide insights into opportunities of how modelling methods may improve the development of automotive software.
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| 10. |
- Mellegård, Niklas, 1971, et al.
(författare)
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Methodology for Requirements Engineering in Model-Based Projects for Reactive Automotive Software
- 2008
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Ingår i: European Conference on Object Oriented Programming, Doctoral symposium.
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Konferensbidrag (refereegranskat)abstract
- With increasing demands on vehicle safety together with the steep growth in software-controlled functions in contemporary vehicles, the demand for a software-focused development model becomes ever more apparent. There are a number of automotive-domain-specific obstacles that prevent development methods from keeping up with the current trends in more traditional software intensive areas. This paper outlines an empirical research project that focuses on introducing relevant concepts from MDSD to the automotive software development process applied at Volvo Car Corporation in order to raise the level of abstraction during software development. The anticipated outcome of this project is a new method for working with model-based software projects with particular focus on non-functional safety requirements.
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