Eliciting dependability requirements: a control cases based approach

Abstract

At present, great demands are posed on software dependability. But how to elicit the dependability requirements is still a challenging task. This paper proposes a novel approach to address this issue. The essential idea is to model a dependable software system as a feedforward-feedback control system, and presents the use cases + control cases model to express the requirements of the dependable software systems. In this model, while the use cases are adopted to model the functional requirements, two kinds of control cases (namely the feedforward control cases and the feedback control cases) are designed to model the dependability requirements. The use cases + control cases model provides a unified framework to integrate the modeling of the functional requirements and the dependability requirements at a high abstract level. To guide the elicitation of the dependability requirements, a HAZOP based process is also designed. A case study is conducted to illustrate the feasibility of the proposed approach.