摘要:

CORE is an established requirements modelling method which employs diagrams and natural language supporting text to express the requirements of a system. The paper reports on a project that has investigated the use of formal specification techniques to strengthen CORE. It focuses on the use of the Vienna development method (VDM) with CORE and outlines an experimental investigation of a proposed CORE/VDM approach within the air traffic control domain. In addition, the role of communicating sequential processes (CSP) with CORE is discussed. The paper concludes that VDM complements CORE by improving the semantic definition of the resultant requirements model and also suggests that CSP may be used to complement VDM in order to portray the dynamic and compositional aspects of a CORE model.

DOI:10.1049/sej.1995.0006

出版商:IEE    

年代:1995

数据来源: IET

摘要:

If a software failure leads to injury or death, legal liability may fall on manufacturers, designers and software engineers. Allegations of negligence may result, and a demonstration of competence is likely to be important in a defence of such allegations. In the absence of authoritative case law, we examine other fields of engineering to obtain an indication as to how, in an action of negligence, the civil courts might measure the competence and behaviour of software engineers in producing safety-related software. We consider the implications of standards and codes of practice, responsibilities of client and contractor, budgetary implications, the status of experts, and the distinction between pioneering design and negligent behaviour. This paper is, however, intended for an engineering readership and legal detail is kept to a minimum.

DOI:10.1049/sej.1995.0007

出版商:IEE    

年代:1995

数据来源: IET

摘要:

Mathematically-based specification techniques are increasingly being recruited to support the development of safety-critical systems. Formal notations, such as Z and VDM, provide precise and concise means of representing a design without forcing commitment to implementation strategies during the early stages of development. Unfortunately, interface requirements are not normally considered within formal specifications. This threatens user-centred design. A prime objective in the use of formal methods is to minimise the modifications that are necessary once a specification has been refined towards implementation. Usability considerations therefore run the risk of being relegated to an afterthought in the development process. The paper argues that temporal and presentation issues must be represented within formal specifications of interactive systems.

DOI:10.1049/sej.1995.0008

出版商:IEE    

年代:1995

数据来源: IET

摘要:

The aim of this paper is to generalise the Fenton-Whitty-Kaposi (FWK) approach to structure software metrics by considering arbitrary sets of decomposition operations for flowgraphs. In the FWK approach, decomposition of flowgraphs is unique, but the number of associated metric functions is not finite and these functions are all independent. In general, the decomposition of flowgraphs is not unique, which leads to constraints on the associated metric functions. Here we derive these constraints explicitly for two special cases, where we consider only the two operations sequencing and nesting as decomposition operations. It is shown that the two resulting classes of structure metrics are contained in the class of recursive structure metrics of the FWK approach.

DOI:10.1049/sej.1995.0009

出版商:IEE    

年代:1995

数据来源: IET

摘要:

Static analysis within industrial applications provides a means of gaining higher assurance for critical software. This survey notes several problems, such as the lack of adequate standards, difficulty in assessing benefits, validation of the model used and acceptance by regulatory bodies. It concludes by outlining potential solutions and future directions.

DOI:10.1049/sej.1995.0010

出版商:IEE    

年代:1995

数据来源: IET