Andreas Vogelsang

Introduction to the SPES Modeling Framework

The aim of model-based development is to use models as main development artifacts in all phases of the development process.

A formal systems engineering approach in practice: an experience report

This paper reports on a successful research transfer project executed in collaboration between Siemens AG, fortiss GmbH and Technische Universität München. The goal of the project was to evaluate if the SPES modeling framework (SPES MF), which has recently been developed by an industrial and academic consortium, and which is implemented within the tool AutoFOCUS3, can be directly applied to a real-life, productive, industrial system. To achieve this, we performed a case study, in which we created models for requirements and functionality for a part of a Siemens train automation system. The results indicate that the SPES MF can indeed be beneficially used in this context. Furthermore, by applying such a structured modeling approach, we were able to reveal several issues in the original requirements specifications. In this paper, we report on our experiences in setting up and performing such kind of collaboration between industry and academia. We discuss the success factors as well as problems that we encountered during the project.

Software metrics in static program analysis

Software metrics play an important role in the management of professional software projects. Metrics are used, e.g., to track development progress, to measure restructuring impact and to estimate code quality. They are most beneficial if they can be computed continuously at development time. This work presents a framework and an implementation for integrating metric computations into static program analysis. The contributions are a language and formal semantics for user-definable metrics, an implementation and integration in the existing static analysis tool GOANNA, and a user-definable visualization approach to display metrics results. Moreover, we report our experiences on a case study of a popular open source code base.

Bridging the Gap between Systems and Software Engineering by Using the SPES Modeling Framework as a General Systems Engineering Philosophy

A multitude of disciplines is involved in the engineering of embedded systems. One major challenge of engineering these systems is to consider the synchronization between different engineering disciplines on the process and artifact level in a coherent manner. Process standards address this challenge by defining a transition between the involved activities of the disciplines but they do not provide sufficient support with respect to the corresponding artifacts and their relationships. The missing artifact-oriented integration of the engineering disciplines (e.g. electrical engineering, software engineering, and mechanical engineering) within the systems engineering process leads to error-prone and cost-intensive synchronizations. In recent years, we participate in a consortium of more than twenty partners from academia and industry that jointly developed the SPES (Software Platform Embedded Systems) Modeling Framework (SPES MF) to support a seamless artifact-based engineering of software for embedded systems. In this paper, we present an approach that fosters the close integration of systems engineering and software engineering activities based on ISO/IEC 15288 and ISO/IEC 12207, by using the core concepts of the SPES MF as a general engineering philosophy for the architectural design of embedded systems.

Systematic elicitation of mode models for multifunctional systems

Many requirements engineering approaches structure and specify requirements based on the notion of modes or system states. The set of all modes is usually considered as the mode model of a system or problem domain.

How to Specify Non-Functional Requirements to Support Seamless Modeling? A Study Design and Preliminary Results

Context: Seamless model-based development provides integrated chains of models, covering all software engineering phases. Non-functional requirements (NFRs), like reusability, further play a vital role in software and systems engineering, but are often neglected in research and practice. It is still unclear how to integrate NFRs in a seamless model-based development. Goal: Our long-term goal is to develop a theory on the specification of NFRs such that they can be integrated in seamless model-based development. Method: Our overall study design includes a multi-staged procedure to infer an empirically founded theory on specifying NFRs to support seamless modeling. In this short paper, we present the study design and provide a discussion of (i) preliminary results obtained from a sample, and (ii) current issues related to the design. Results: Our study already shows significant fields of improvement, e.g., the low agreement during the classification. However, the results indicate to interesting points; for example, many of commonly used NFR classes concern system modeling concepts in a way that shows how blurry the borders between functional and NFRs are. Conclusions: We conclude so far that our overall study design seems suitable to obtain the envisioned theory in the long run, but we could also show current issues that are worth discussing within the empirical software engineering community. The main goal of this contribution is not to present and discuss current results only, but to foster discussions on the issues related to the integration of NFRs in seamless modeling in general and, in particular, discussions on open methodological issues.

Extent and characteristics of dependencies between vehicle functions in automotive software systems

Functional dependencies and feature interactions are a major source of erroneous and unwanted behavior in software-intensive systems. To overcome these problems, many approaches exist that focus on modeling these functional dependencies in advance, i.e., in the specification or the design of a system. However, there is little empirical data on the amount of such interactions between system functions in realistic systems. In this paper, we analyze structural models of a modern realistic automotive vehicle system with the aim to assess the extent and characteristics of interactions between system functions. Our results show that at least 69% of the analyzed system functions depend on each other or influence each other. These dependencies stretch all over the system whereby single system functions have dependencies to up to 40% of all system functions. These results challenge the current development methods and processes that treat system functions more or less as independent units of functionality.

Early Validation of Automation Plant Control Software using Simulation Based on Assumption Modeling and Validation Use Cases

In automation plants, technical processes must be conducted in a way that products, substances, or services are produced reliably, with sufficient qual- ity and with minimal strain on resources. A key driver in conducting these pro- cesses is the automation plants control software, which controls the technical plant components and thereby affects the physical, chemical, and mechanical processes that take place in automation plants. To this end, the control software of an automation plant must adhere to strict process requirements arising from the technical processes, and from the physical plant design. Currently, the vali- dation of the control software often starts late in the engineering process in many cases - once the automation plant is almost completely constructed. However, as widely acknowledged, the later the control software of the automa- tion plant is validated, the higher the effort for correcting revealed defects is, which can lead to serious budget overruns and project delays. In this article we propose an approach that allows the early validation of automation control software against the technical plant processes and assumptions about the physi- cal plant design by means of simulation. We demonstrate the application of our approach on the example of an actual plant project from the automation industry

How do Practitioners Perceive the Relevance of Requirements Engineering Research? An Ongoing Study

The relevance of Requirements Engineering (RE) research to practitioners is a prerequisite for problem-driven research in the area and key for a long-term dissemination of research results to everyday practice. To understand better how industry practitioners perceive the practical relevance of RE research, we have initiated the RE-Pract project, an international collaboration conducting an empirical study. This project opts for a replication of previous work done in two different domains and relies on survey research. To this end, we have designed a survey to be sent to several hundred industry practitioners at various companies around the world and ask them to rate their perceived practical relevance of the research described in a sample of 418 RE papers published between 2010 and 2015 at the RE, ICSE, FSE, ESEC/FSE, ESEM and REFSQ conferences. In this paper, we summarize our research protocol and present the current status of our study and the planned future steps

On the distinction of functional and quality requirements in practice

Requirements are often divided into functional requirements (FRs) and quality requirements (QRs). However, we still have little knowledge about to which extent this distinction makes sense from a practical perspective. In this paper, we report on a survey we conducted with 103 practitioners to explore whether and, if so, why they handle requirements labeled as FRs differently from those labeled as QRs. We additionally asked for consequences of this distinction w.r.t. the development process. Our results indicate that the development process for requirements of the two classes strongly differs (e.g., in testing). We identified a number of reasons why practitioners do (or do not) distinguish between QRs and FRs in their documentation and we analyzed both problems and benefits that arise from that. We found, for instance, that many reasons are based on expectations rather than on evidence. Those expectations are, in fact, not reflected in specific negative or positive consequences per se. It therefore seems more important that the decision whether to make an explicit distinction or not should be made consciously such that people are also aware of the risks that this distinction bears so that they may take appropriate countermeasures.