QoS-aware query relaxation for service discovery with business rules

•We propose an annotation mechanism to describe business-driven QoS.•We propose a business-driven filtering mechanism to eliminate unsuitable services.•We propose a ranking method based on QoS preferences and constraints.•We propose query relaxation methods for single service query or composite one.•Experimental results show that the proposal can effectively discover services.

Service discovery, the process of locating web services capable of satisfying the requirements of service requesters, plays a crucial role in the development of user-centric, service-oriented applications; however, most current service discovery mechanisms do not focus on integrating various business-driven quality of service (QoS) attributes or establishing relaxation mechanisms to enhance search results. This research proposes a systematic approach, referred to as business-rule-based service discovery (BRSD), to address the above issues. The main features of the proposed approach are as follows: (1) a business rule annotation mechanism that includes condition rules, enumeration rules, and applied utility references; (2) the ability to eliminate unsuitable services through the application of filters to deal with kernel properties, provider constraints, and user constraints; (3) the calculation of service ranking scores for single services or service sets according to QoS constraints and QoS importance ranking; and (4) the ability to retrieve suitable single services as well as service sets using the proposed two-point and incremental service query relaxation mechanisms.