An Automatic Requirements Negotiation Approach for Business Services

Organizations now resort to service-orientation as it enables them to quickly create and offer new business services (BSs) or optimize existing ones. In many cases, organizations must cooperate to offer such services so as to concentrate only on their core business. An initial phase to the design of a novel BS concerns the determination of the BS's functional and non-functional requirements. The respective research approaches exploit goal models to specify and elicit such requirements. However, while it is easy to reach an agreement for the functional requirements, this is not true for the non-functional ones. First, as the involved stakeholders may have different requirements and expertise level for particular non-functional aspects. Second, as a BS's non-functional performance is critical for distinguishing among functionally-equivalent BSs of other competing organizations. Thus, the stakeholders must negotiate over the BS's non-functional requirements. However, such a negotiation may take considerable time and needs the active stakeholder involvement in terms of alternative offers for the conflicting requirements. To this end, this paper proposes a broker-based BS negotiation framework that can automatically determine the non-functional requirements of the required BS. This framework takes as input a functional goal model as well as the stakeholder requirements in terms of utility functions on the non-functional performance of the required BS functional goal and its sub-goals, and can propose an overall solution that is balanced and consistent across the goal model levels and satisfies as much as possible all the stakeholders.