In industrial projects, commonly a large number of work products needs to be created and managed. Explicitly documented models of the artifacts under development may assist in planning the structure of work products and defining the processes used for requirements development and management. In our experience, however, industrial organizations often do not explicitly define and capture requirements artifact models, because creating a documented artifact model is often perceived as having a high cost, while the benefits of its use are seen as unclear. This paper describes the analysis of the use of requirements artifact models in four industrial projects. The analysis results describe benefits of artifact models in industrial environments and six lessons learned that guide practitioners to a more effective and efficient use of such models.

Requirements engineering is arguably the most important activity in the development of complex, software-intensive systems. Generally, the higher the complexity of the system under development, the more exacerbated the importance of good requirements engineering becomes. While numerous researchers in academia have focused on requirements engineering, there is still a need for practical guidelines that scale to real-world applications. This paper presents requirements engineering challenges faced and lessons learned addressing these challenges in a large-scale industrial project. The implementation of these lessons greatly contributed to the success of the project.

Models are frequently used for illustrations in software design documents. Commonly they are used to show static structure and less often, external dynamic behavior. However, in software engineering, the lack of conceptual models often inhibits creativity and understanding, which may in turn lead to incomplete or poor design. This paper describes our experience using models for the architectural, conceptual and detailed design for software systems, identifies perceived weaknesses in traditional approaches and makes recommendations for future modeling tools and techniques.

Explicitly addressing fault-tolerance during the requirements analysis phase facilitates the early detection of inconsistencies between functional and fault-tolerance requirements, which could potentially reduce the overall development costs. Most existing approaches use redundancy of services as a means to mask faults, where it is difficult to provide a systematic approach for modeling and analyzing the effect of faults on functional requirements during use case analysis. Moreover, providing masking fault-tolerance could be costly or impractical. This paper overviews a systematic approach for use case-based modeling of faults and failsafe fault-tolerance, where a failsafe fault-tolerant system at least meets its safety requirements when faults occur

No abstract available

Embedded systems are pervasive and frequently used for critical systems with time-dependent functionality. Dwyer et al. (1999) have developed qualitative specification patterns to facilitate the specification of critical properties, such as those that must be satisfied by embedded systems. Thus far, no analogous repository has been compiled for realtime specification patterns. This paper makes two main contributions: First, based on an analysis of timing-based requirements of several industrial embedded system applications, we created real-time specification patterns in terms of three commonly used real-time temporal logics. Second, as a means to further facilitate the understanding of the meaning of a specification, we offer a structured English grammar that includes support for real-time properties. We illustrate the use of the real-time specification patterns in the context of property specifications of a real-world automotive embedded system.

Formal specification languages are often perceived as difficult to use by practitioners, and are therefore rarely-used in industrial software development practices. Numerous researchers have developed specification pattern systems to facilitate the construction of formal specifications of system properties. Feedback indicates that these patterns are considered helpful, but many practitioners prefer capturing properties using informal notations, such as natural language, instead of formal specification languages. This paper describes a project that addresses this technology gap. First, we introduce a stepwise process for deriving and instantiating system properties in terms of their natural language representations. The key components of this process are structured natural language grammars and specification pattern systems. Second, we describe SPIDER, a prototype implementation of a tool suite supporting this specification process. We illustrate the use of our approach with a description of a stepwise construction process of property specifications of a real-world automotive embedded system using Spider.

Some of the most challenging tasks in building a software system are capturing, refining, and analyzing requirements. How well these tasks are performed significantly impacts the quality of the developed software system. The difficulty of these tasks is greatly exacerbated for the software of embedded systems as these systems are commonly used for critical applications, have to operate reliably for long periods of time, and usually have a high degree of complexity. Current embedded systems software development practice, however, often deals with the (requirements) analysis phase in a superficial manner, instead emphasizing design and implementation. This research investigates how an approach similar to the well-known design patterns, termed object analysis patterns, can be applied in the analysis phase of embedded systems development, prior to design and coding. Specifically, our research explores how object-oriented modeling notations, such as the Unified Modeling Language (UML), can be used to represent structural and behavioral information as part of commonly occurring object analysis patterns. This work also investigates how UML-based conceptual models of embedded systems, based on the diagram templates in the object analysis patterns, can be automatically analyzed using the Spin model checker for adherence to properties specified in linear-time temporal logic (LTL) using a previously developed UML formalization framework. We have applied these patterns to several embedded systems applications obtained from the automotive industry. This paper describes one of our case studies and illustrates how our approach facilitates the construction of UML-based conceptual models of embedded systems and the analysis of these models for adherence to functional requirements.

In software engineering, design patterns propose solution skeletons for common design problems. The solution skeleton is described in such a way that the design can be used for other projects, where each application tailors the design to specific project constraints. This paper describes research into investigating how a similar approach to reuse can be applied to requirements specifications, which we term requirements patterns. Specifically, the paper explores how object-oriented modeling notations, such as the Unified Modeling Language (UML), can be used to represent common requirements patterns. Structural and behavioral information are captured as part of a requirements pattern. In order to maximise reuse, we focus on requirements patterns for embedded systems. This paper also describes case studies that illustrate how we have applied these general patterns to multiple embedded systems applications from the automotive industry.