Evolvable Integration of Activities with Statecharts

The dynamic behavior of a system can be specified in statecharts,\ud and the activities of the system can be implemented in terms of\ud functions in the C programming language. Later, the statecharts\ud and the activities can be integrated to realize the system that\ud fulfils a given set of requirements.\ud \ud After the integration, the statecharts, the activities, and the\ud requirements are subject to change due to emerging necessities\ud such as bug fixes. Any change to any of these artifacts has a cost\ud in terms of effort, and risk of errors.\ud \ud In this paper, we provide a rigorous analysis of a relevant subset\ud of possible changes to activities, and their associated costs. In\ud addition, we present the overview of our solution to reduce these\ud costs.\u

Designing and Documenting the Behavior of Software

The development and maintenance of today's software systems is an increasingly effort-consuming and error-prone task. A major cause of this problem is the lack of formal and human-readable documentation of software design. In practice, software design is often informally documented (e.g. texts in a natural language, `boxes-and-arrows' diagrams without well-defined syntax and semantics, etc.), or not documented at all. Therefore, the design cannot be properly communicated between software engineers, it cannot be formally analyzed, and the conformance of an implementation to the design cannot be formally verified.\ud \ud In this chapter, we address this problem for the design and documentation of the behavior implemented in procedural programs. We introduce a solution that consists of three components: The first component is a graphical language called VisuaL, which enables engineers to specify constraints on the possible sequences of function calls from a given program. Since the specifications may be inconsistent with each other, the second component of our solution is a tool called CheckDesign, which automatically\ud verifies the consistency between multiple specifications written in VisuaL. The third component is a tool called CheckSource, which automatically verifies that a given implementation conforms to the corresponding specifications written in VisuaL.\ud \ud This solution has been evaluated empirically through controlled experiments with 71 participants: 23 professional developers of ASML, and 49 Computer Science M.Sc. students. These experiments showed that, with statistical significance of 0.01, the solution reduced the effort of typical maintenance tasks by 75% and\ud prevented one error per 140 lines of source code

Towards an Expressive and Scalable Framework for expressing Join Point Models

Join point models are one of the key features in aspectoriented programming languages and tools. They provide\ud software engineers means to pinpoint the exact locations in programs (join points) to weave in advices. Our experience in modularizing concerns in a large embedded system showed that existing join point models and their underlying program representations are not expressive enough. This prevents the selection of some join points of our interest. In this paper, we motivate the need for more fine-grained join point models within more expressive source code representations. We propose a new program representation called a program graph, over which more fine-grained join point models can be defined. In addition, we present a simple language to manipulate program graphs to perform source code transformations. This language thus can be used for specifying complex weaving algorithms over program graphs

Creating high-quality behavioural designs for software-intensive systems

In todays industrial practice, behavioral designs of software-intensive systems such as embedded systems are often imprecisely documented as plain text in a natural language such as English, supplemented with ad-hoc diagrams. Lack of quality in behavioral design documents causes poor communication between stake holders, up to 100 times more costly rework during testing and integration, and hard-to-maintain documents of behavioral designs. To address these problems, we present a solution that involves the usage of (a) data-flow diagrams to document the input-output relation between the actions performed by a software-intensive system, (b) control-flow diagrams to document the possible sequences of actions performed by the system, and \ud (c) Vibes diagrams to document temporal or logical constraints on the possible sequences of actions performed by the system. The key benefit of this solution is to improve the separation of concerns within behavioral design documents; hence to improve their understandability, maintainability, and evolvabilit

Evolvable Behavior Specifications Using Context-Sensitive Wildcards

The development and maintenance of today's software systems is an increasingly effort-consuming and error-prone task. A major cause of the effort and errors is the lack of human-readable and formal documentation of software design. In practice, software design is often informally documented, or not documented at all. Therefore, (a) the design cannot be properly communicated between software engineers, (b) it cannot be automatically analyzed for finding and removing faults, (c) the conformance of an implementation to the design cannot be automatically verified, and (d) source code maintenance tasks have to be manually performed, although some of these tasks can be automated using formal documentation. In this thesis, we address these problems for the design and documentation of the behavior implemented in procedural programs. We present the following solutions each addressing the respective problem stated above: (a) A graphical language called VisuaL, which enables engineers to specify constraints on the possible sequences of function calls from a given procedural program, (b) an algorithm called CheckDesign, which automatically verifies the consistency between multiple specifications written in VisuaL, (c) an algorithm called CheckSource, which automatically verifies the consistency between a given implementation and a corresponding specification written in VisuaL, and (d) an algorithm called TransformSource, which uses VisuaL specifications for automatically inserting additional source code at well-defined locations in existing source code. Empirical evidence indicates that CheckSource is beneficial during some of the typical control-flow maintenance tasks: 60% effort reduction, and prevention of one error per 250 lines of source code. These results are statistically significant at the level 0,05. Moreover, the combination of CheckSource and TransformSource is beneficial during some of the typical control-flow maintenance tasks: 75% effort reduction, and prevention of one error per 140 lines of source code. These results are statistically significant at the level 0,01. The main contribution of this thesis is the graphical language VisuaL with its formal underpinning Deterministic Abstract Recognizers (DARs), which defines a new family of formal languages called Open Regular Languages (ORLs). The key feature of VisuaL is the context-sensitive wildcard, which makes VisuaL specifications more evolvable (i.e. less susceptible to changes), and more concise

Generic, Property Based Queries for Evolvable Weaving Specifications

In the current aspect-oriented languages, advices and pointcuts are explicitly associated in general. This results in weaving specifications that are less evolvable and need more maintenance during the development of a system. To address this issue, we propose associative access to advices and aspects: a designating mechanism that allows for referring aspect/advices through their (syntactic and semantic) properties in advice-pointcut bindings. First, this paper presents an extensive analysis of the advicepointcut binding mechanisms of the state-of-the-art AOP approaches. Based on this analysis, we extend the current weaving (superimposition) specification of our aspect-oriented approach, Compose*. In the new specification, we apply queries that can designate filtermodules and other type of units (e.g. annotations) based on their properties. As an evaluation of our work, we present a tradeoff analysis about the new weaving specification with respect to several software engineering properties, in particular expressiveness, evolvability and comprehensibility. Finally, the paper ends with related works and conclusion