ScenarioTools Real-Time Play-Out for Test Sequence Validation in an Automotive Case Study

In many areas, such as automotive, healthcare, or production, we find software-intensive systems with complex real-time requirements. To efficiently ensure the quality of these systems, engineers require automated tools for the validation of the requirements throughout the development. This, however, requires that the requirements are specified in an analyzable way. We propose modeling the specification using Modal Sequence Diagrams (MSDs), which express what a system may, must, or must not do in certain situations. MSDs can be executed via the play-out algorithm to investigate the behavior emerging from the interplay of multiple scenarios; we can also test if traces of the final product satisfy all scenarios. In this paper, we present the first tool supporting the play-out of MSDs with real-time constraints. As a case study, we modeled the requirements on gear shifts in an upcoming standard on vehicle testing and use our tool to validate externally generated gear shift sequences

Model-Based Requirements Engineering in the Automotive Industry: Challenges and Opportunities

Context:The automotive industry is faced with rapid increases in size and complexity of their software engineering efforts, which makes successful Requirements Engineering essential. Model-Based Engineering has been suggested as a method to handle increasing complexity on a higher level of abstraction. Using models already during Requirements Engineering could offer several benefits, as changes are quick and cheap to implement. However, due to the high level of uncertainty and abstraction from implementation, it is unclear whether models can be used in the same way during Requirements Engineering as during later project stages.Objective:The overall aim of this PhD project is to simplify the introduction of Model-Based Requirements Engineering in an automotive environment, based on objective guidelines. These guidelines should enable engineers and decision makers to decide on important factors such as the point of time or appropriate abstraction levels for requirement models. As a first step in this direction, the contribution of this thesis is an overview of the current industrial practice of Model-Based Engineering and Requirements Engineering in the automotive industry and initial results on how automotive requirements models can be created and exploited for testing purposes.Method:Results of this thesis are obtained using the three empirical strategies case study, controlled experiment and survey. Additionally, improvements are suggested using one study following the engineering paradigm, proposing and evaluating improvements to existing solutions.Results and Conclusions:The thesis outlines the general feasibility of models during automotive Requirements Engineering. Findings are that Model-Based Engineering is widespread in the automotive domain and used for Requirements Engineering by some practitioners. However, several problems exist in the Requirements Engineering practices of automotive companies. As a part of these, we report problems with respect to communication and organisation structure. We show that behaviour requirements from an emission standard draft can be formalised as models and used as test oracles. Furthermore, we compare two notations for formalising behaviour of an automotive requirements specification. The results indicate that languages can be chosen based on other factors than the notation, such as tool support or experience.Future Work:There are several directions for future work. For example, high-level requirements can be re-used as test oracles on different abstraction and testing levels. Additionally, communication in Requirements Engineering could be improved by using existing model-based requirements specifications and ownership relations between requirements and stakeholders

An Empirical Investigation of Using Models During Requirements Engineering in the Automotive Industry

Context:The automotive industry is undergoing a major transformation from a manufacturing industry towards an industry that relies heavily on software. As one of the main factors for project success, requirements engineering (RE) plays a major role in this transition. Similar to other areas of automotive engineering, the use of models during RE has been suggested to increase productivity and tackle increasing complexity by means of abstraction. Existing modelling frameworks often prescribe a variety of different, formal models for RE, trying to maximise the benefit obtained from model-based engineering (MBE). However, these frameworks are typically based on assumptions from anecdotal evidence and experience, without empirical data supporting these assumptions.Objective:The overall aim of our research is to investigate the potential benefits and drawbacks of using model-based RE in an automotive environment based on empirical evidence. To do so, we present an investigation of the current industrial practice of MBE in the automotive industry, existing challenges in automotive RE, and potential use cases for model-based RE. Furthermore, we explore two use cases for model-based RE, namely the creation of behavioural requirements models for validation and verification purposes and the use of existing trace models to support communication.Method:We address the aims of this thesis using three empirical strategies: case study, design science and survey. We collected quantitative and qualitative data using interviews as well as questionnaires.Results:Our results show that using models during automotive RE can be beneficial, if restricted to certain aspects of RE. In particular, models supporting communication and stakeholder interaction are promising. We show that the use of abstract models of behavioural requirements are considered beneficial for system testing purposes, even though they abstract from the detailed functional requirements. Furthermore, we demonstrate that existing data can be understood as a model to uncover dependencies between stakeholders. Conclusions:Our results question the feasibility to construct and maintain large amounts of formal models for RE. Instead, models during RE should be used for a few, important use cases. Additionally, MBE can be used as a means to understand existing problems in software engineering