Cluster-oriented service composition modeling method based on logical net units

A logical net unit (LNU) model is defined according to logical Petri nets (LPNs). The Web service composition takes a service cluster as a minimal granularity for the first time, and a service cluster is formally modeled by an LNU in a virtual layer. The composition of service cluster model LNUs generates Service Nets and the basic composite patterns of LNU models are discussed. And the Service Nets properties are discussed. The efficiency of Web service composition is improved by the proposed method. A Travel service example is proposed to illustrate the modeling method.