Integration of Functional and Interface Requirements of an Web based Software: A VDM based Formal Approach

Abstract

Analysing user requirements properly is the key to any software development process. In contemporary web based software developments the user interface requirements are predominant among the non functional requirements. The end-users’ involvement in interface requirements has made it challenging for the designers to map these interface requirements with functional requirements. As a consequence we often use different specification languages for different types of requirements but then interface requirements, if handled separately May lead to traceability problem for the developers, especially in web based application development. In order to make requirements analysis both comprehensible and rigorous, formal requirements specification methods are very important. In this paper we have tried to describe how interface requirements can be specified in a formal way in connection with the functional requirements for a better understanding in designing. The Vienna Development Method Specification Language (VDM-SL) being a well established formalizing tool for user requirements specification, we propose some add-ons to this tool to help in formalizing these types of requirements. We have also used this technique in a case study to strengthen our proposal.