This paper reports the action research conducted into the issues of introducing structure into informal information requirements for deciding which constructs are appropriate for describing information requirements. The outcome of this research was the development of a Business Rules Diagram (BRD) and a technique for assisting its construction. A critical epistemological gap is asserted to exist between those who capture information requirements in human activity systems (typically, informally) and those who specify and deliver information systems. The paper demonstrates how modelling business rules can bridge that gap. A definition of a business rule and also a complete description of the notation of the BRD and the steps for its creation are provided.
The term Information Requirements Determination (IRD) is often used when the focus of requirements engineering relates to information systems (as opposed to say, real-time systems or telecommunication systems) since there are arguably facets of information systems which are unique or distinct from other domains. Most authors split the process of IRD into two main steps—requirements acquisition and requirements modelling (Valusek and Fryback, 1987; and Greenspan et al., 1994), although there are exceptions to this (Vitalari, 1992). Currently, there is much interest in the problems of the early stages of IRD concerned with acquiring or eliciting requirements. For example, Vidgen (1997) looks at stakeholder approaches, Darke and Shanks (1997) examine a related concept known as viewpoint modelling, and Flynn and Davarpanah (1998) recommend user-led construction of requirements. Other issues with requirements elicitation include emergent requirements, which is to say that users at the beginning of the IRD process are either not fully conversant with requirements, or have not fully thought through the implications of requirements (Goguen and Linde, 1993; and Leifer et al., 1994). Clearly, clarifying and agreeing on requirements, especially when political factions are involved or competing interests have to be traded off, is an important early first step before proceeding with the implementation of an information system.
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