Three Types of Requirements Engineering

What is the starting point for an SOA modeling exercise? Traditionally, we have often understood the purpose of modeling in terms of the design of a specific or generic solution to some business problem or opportunity. But with the service-based business, we may have to start further back – modeling the business ecosystem in order to identify problems and opportunities in the first place.

In the service economy, the business focus is to provide value-adding services to its customers. What you as a business have to decide is: what is a reasonable and economically viable set of services to offer. And then you build a platform of services. This is not a complete solution to one problem – it is a partial solution to many different problems, in many different contexts. That's how you get reuse, economics of scale and scope, and ultimately business viability.

So we have three types of requirements engineering, as shown in the following table.

Solution-Driven (Specific)	Solution-Driven (General)	Evolution-Driven
Identify Business Problem Identify "Users" Negotiate Requirements Define Solution	Identify Domain Identify Domain Experts Define Requirements Design Solution Kit	Identify Ecosystem Identify Services Procure and Release Devices

Extract from Business Modelling for SOA (CBDI Journal, March 2005)