摘要:In the field of service-oriented systems, a service is considered as an artifact that has a logical representation. However, the logical boundary of a service is not clearly defined. In particular, it needs to be defined clearly at the design level. Without such a definition, it is not possible to delineate outgoing coupling of a service. It would be difficult to analyze overall static, inter-modular coupling of a service. Further, one cannot devise effective metrics for design characteristics like complexity, cohesion and coupling of a service. A definition that is both technology-agnostic and independent of the physical packaging of a service would be most suitable. This paper defines clearly the logical boundary of a service and makes other improvements to a generic formal model. Thus, it presents a comprehensive formal model that leads to novel metrics and helps in explaining microservices architecture as a special case.