Requirements Modelling and Specification for Service Oriented Architecture

1.2. Aligning IT with Business - Speaking a Common Language

To believe that adopting the latest technology fad, be it service oriented architecture, business process modelling or even a business rules management system will, on its own, solve this problem is nothing short of naïve. To align IT with business we must consider all these along with innovative approaches to requirements engineering and system modelling.

The problem of requirements engineering is a modelling problem. We must model the business: its processes, its goals, its systems, its people and structure and even its culture. But we also need to model potential solutions: in this context, networks of loosely coupled services (applications) that make sense to the business and contribute to its goals. Ideally, the services (the technology, if you must) will map clearly onto the business needs and processes. This implies that we need a language rich enough to describe both the business and its systems and, more importantly, a language that can be understood by all stakeholders.

If one adopts the common misconception that understanding a client's requirements is the same as specifying a system that will meet those requirements, one can then blithely infer that use case analysis is the only requirements modelling technique needed. Jackson (1998) pours scorn on this idea, arguing that use cases are useful for specifying systems but that they cannot describe requirements fully. Use cases connect actors - which represent ...