Howard P. Haughton

Specification in B: An Introduction Using the B Toolkit

Offers a practical introduction to the B specification language and method, an approach to the development of high-quality software using rigorous CASE techniques. Examples of all development life-cycle stages are given in the work, including animation, proof, design and code generation in C. Two case studies and excercises with solutions are provided.

Reverse engineering COBOL via formal methods

We describe methods and software tools which aid in reverse-engineering COBOL application programs back to specifications (and in validating them against specifications). The aim is to create object-based abstractions from the implementation to capture design and functionality. The central process which the tools support is ‘transformation from formalism to formalism’, first from COBOL to the intermediate language Uniform, then from Uniform to a functional description language, and then to the specification language Z. In the process, dataflow diagrams, entity-relationship diagrams and call-graphs, and other types of information, are extracted from the code.

Reasoning and Refinement in Object-Oriented Specification Languages

This paper describes a formal object-oriented specification language, Z++, and identifies proof rules and associated specification structuring and development styles for the facilitation of validation and verification of implementations against specifications in this language. We give inference rules for showing that certain forms of inheritance lead to refinement, and for showing that refinements are preserved by constructs such as promotion of an operation from a supplier class to a client class. Extension of these rules to other languages is also discussed.

Formal development in B abstract machine notation

Abstract This paper gives a comprehensive introduction to the B Abstract Machine Notation (AMN), a formal method which is based on Z and which is supported by an industrial quality toolset. The paper describes development techniques for AMN, including the formalization of requirements, specification construction, design and implementation. Results from a large-scale safety-critical development using the method are also given.

A specification-based approach to maintenance

In this paper we define a language, Z++, and a method based upon this language, to support the use of formal methods in software maintenance. Formal methods have been proposed several times as the solution to the growing problem of software maintenance, and we base our approach on the more successful of the attempts made to apply these methods. Our approach is to use a conceptually simple framework, based on an object-oriented extension to the specification language Z (Spivey, 1989), for dealing with requests for changes to software for which some formal documentation and record of development already exists. The method is centered on the maintenance of the specifications and the development record, not upon source code or Structured Methodology documentation. It is proposed as a practical approach for software in the medium-term future, allowing the mass of programming detail that makes the code maintenance problem so expensive to be ignored. Therefore changes and extensions to application systems can be made more rapidly. We describe the language and give details of the specification and refinement system, together with a description of the current state of the implementation of this system.

The Impact of Integrating Agile Software Development and Model-Driven Development: A Comparative Case Study

Agile and Model-Driven Development integration (Agile MDD) is of significant interest to researchers who want to leverage the best of both worlds. Currently, there is no clear evidence or proof for the real impact of such integration. As a first step in this direction, this paper reports an empirical investigation on the impact of integrating Agile and Model-Driven Development on the quality of software systems. To this end, we developed a financial application using Agile MDD, which is further contrasted with three other independent versions of the same application developed using different approaches: Agile method, MDD method, and traditional (manually-coded) method, respectively. We also compared the functionality of the systems and a variety of technical debt metrics measuring the quality of the code and its design. Based on the case study results, we have found that the use of Agile MDD shows some improvements in the product quality and efficiency.