TAPAs: A Tool for the Analysis of Process Algebras

Process algebras are formalisms for modelling concurrent systems that permit mathematical reasoning with respect to a set of desired properties. TAPAs is a tool that can be used to support the use of process algebras to specify and analyze concurrent systems. It does not aim at guaranteeing high performances, but has been developed as a support to teaching. Systems are described as process algebras terms that are then mapped to labelled transition systems (LTSs). Properties are verified either by checking equivalence of concrete and abstract systems descriptions, or by model checking temporal formulae over the obtained LTS. A key feature of TAPAs, that makes it particularly suitable for teaching, is that it maintains a consistent double representation of each system both as a term and as a graph. Another useful didactical feature is the exhibition of counterexamples in case equivalences are not verified or the proposed formulae are not satisfied

Requirements Engineering

Requirements Engineering (RE) aims to ensure that systems meet the needs of their stakeholders including users, sponsors, and customers. Often consid- ered as one of the earliest activities in software engineering, it has developed into a set of activities that touch almost every step of the software development process. In this chapter, we reflect on how the need for RE was first recognised and how its foundational concepts were developed. We present the seminal papers on four main activities of the RE process, namely (i) elicitation, (ii) modelling & analysis, (iii) as- surance, and (iv) management & evolution. We also discuss some current research challenges in the area, including security requirements engineering as well as RE for mobile and ubiquitous computing. Finally, we identify some open challenges and research gaps that require further exploration

Message sequence chart specifications with cross verification

Current software specification verification methods are usually performed within the context of the specification method. There is little cross verification, pitting one type of specification against another, taking place. The most common techniques involve syntax checks across specifications or doing specification transformations and running verification within the new context. Since viewpoints of a system are different even within programming teams we concentrate on producing an efficient way to run cross verification on specifications, particularly specifications written with Message Sequence Charts and State Transition Diagrams.;In this work an algorithm is proposed in which all conditional MSCs are transformed into an algebraic representations, Message Flow Graphs and by stepwise refinement, a Global State Transition Graph is created. This GSTG has all the properties of a State Transition Diagram and therefore can be analyzed in conjunction with the original STD

Relationship analysis : improving the systems analysis process

A significant aspect of systems analysis involves discovering and representing entities and their inter-relationships. Guidelines exist to identify entities but do not provide a rigorous and comprehensive process to explicitly capture the relationship structure of the problem domain. Whereas, other analysis techniques lightly address the relationship discovery process, Relationship Analysis is the only systematic, domain-independent analysis technique focusing exclusively on a domain\u27s relationship structure. The quality of design artifacts, such as class diagrams, and development time necessary to generate these artifacts can be improved by first representing the complete relationship structure of the problem domain. The Relationship Analysis Model is the first theory-based taxonomy to classify relationships. A rigorous evaluation was conducted, including a formal experiment comparing novice and experienced analysts with and without Relationship Analysis. It was shown that the Relationship Analysis Process based on the model does provide a fuller and richer systems analysis, resulting in improved quality of and reduced time in generating class diagrams. It also was shown that Relationship Analysis enables analysts of varying experience levels to achieve a similar level of quality of class diagrams. Relationship Analysis significantly enhances the systems analyst\u27s effectiveness, especially in the area of relationship discovery and documentation resulting in improved analysis and design artifacts

Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing

Refining Transformation Rules For Converting UML Operations To Z Schema

The UML (Unified Modeling Language) has its origin in mainstream software engineering and is often used informally by software designers. One of the limitations of UML is the lack of precision in its semantics, which makes its application to safety critical systems unsuitable. A safety critical system is one in which any loss or misinterpretation of data could lead to injury, loss of human lives and/or property. Safety Critical systems are usually specified by very precisely and frequently required formal verification. With the continuous use of UML in the software industry, there is a need to augment the informality of software models produced to remove ambiguity and inconsistency in models for verification and validation. To overcome this well-known limitation of UML, formal specification techniques (FSTs), which are mathematically tractable, are often used to represent these models. Formal methods are mathematical techniques that allow software developers to produce softwares that address issues of ambiguity and error in complex and safety critical systems. By building a mathematically rigorous model of a complex system, it is possible to verify the system\u27s properties in a more thorough fashion than empirical testing. In this research, the author refines transformation rules for aspects of an informally defined design in UML to one that is verifiable, i.e. a formal specification notation. The specification language that is used is the Z Notation. The rules are applied to UML class diagram operation signatures iteratively, to derive Z schema representation of the operation signatures. Z representation may then be analyzed to detect flaws and determine where there is need to be more precise in defining the operation signatures. This work is an extension of previous research that lack sufficient detail for it to be taken to the next phase, towards the implementation of a tool for semi-automated transformation