Semantics of Standard Process Models with ORjoins The Business Process Modeling Notation (BPMN) is an emerging standard for capturing business processes. Like its predecessors, BPMN lacks a formal semantics and many of its features are subject to interpretation. One construct of BPMN that has an ambiguous semantics is the ORjoin. Several formal semantics of this construct have been proposed for similar languages such as EPCs and YAWL. However, these existing semantics are computationally expensive. This paper formulates a semantics of the ORjoin in BPMN for which enablement of a given ORjoin in a model can be evaluated in quadratic time in terms of the total number of elements in the model. This complexity can be reduced to lineartime after materializing a quadraticsized data structure at designtime. The paper also shows how to evaluate enablement of an ORjoin incrementally as the execution of a process instance unfolds.

A RuleBased Language and Verification Framework of Dynamic Service Composition The emergence of BPML (Business Process Modeling Language) has favored the development of languages for the composition of services. Processoriented approaches produce imperative languages, which are rigid to change at runtime because they focus on how the processes should be built. Despite the fact that semantics is introduced in languages to increase their flexibility, dynamism is limited to find services that have disappeared or become defective. They do not offer the possibility to adapt the composite service to execution. Although rulesbased languages were introduced, they remain very much dependent on the BPML which is the underlying technology. This article proposes the specification of a rulebased declarative language for the composition of services. It consists of the syntactic categories which make up the concepts of the language and a formal description of the operational semantics that highlights the dynamism, the flexibility and the adaptability of the language thus defined. This paper also presents a verification framework made of a formal aspect and a toolset. The verification framework translates service specifications into Promela for model checking. Then, a validation framework is proposed that translates the verified specifications to the operational system. Finally, a case study is presented.