Patterns for process-aware information systems : an approach based on colored Petri nets

Organizations are continuously seeking ways to improve the efficiency and effectiveness of their operations. To assist in meeting these objectives, it is increasingly recognized that they require a range of techniques and technologies for managing their organizational business processes. With this need in mind, the Business Process Management (BPM) discipline has been established with the aim of developing approaches to the operationalization of business processes based on software technology. Systems which manage business processes in conjunction with a process model (either explicitly or implicitly) are typically termed Process-Aware Information Systems (or PAISs). The increasing demands of the modern business environment mean that PAISs need to be capable of supporting dynamic organizations in deploying flexible business processes that are subject to ongoing change and evolution and involve the integration of external parties, organizations and software applications. Numerous PAIS offerings have been developed over the past decade resulting in an increasingly diverse range of approaches to modeling and enacting business process concepts. This diversity of techniques has triggered a number of initiatives aimed at establishing common standards in the BPM field. However none of the resultant standards proposals has met with widespread adoptance. In an effort to develop a rigorous conceptual foundation for the domain, the Workflow Patterns Initiative adopted a pattern-based approach to identifying and describing the fundamental requirements for PAISs. The work presented in this thesis contributes to this initiative by refining the conceptual foundation for PAIS, specifically concentrating on the control-flow, service-interaction, and process flexibility perspectives. This thesis addresses these perspectives as follows. The requirements for PAISs from the control-flow perspective are described by (1) a comprehensive set of 43 workflow control-flow patterns, which identify recurring generic constructs relevant to process structure and enactment, and (2) the Core Process Constructs Specification Language that allows different approaches to the operationalization of process constructs to be explicitly described in a language-independent way. The requirements in service interaction are described in the form of a configurable framework, consisting of five pattern families, in total combining 1602 Service Interaction pattern variants. A graphical notation has been developed that encompasses each of the pattern families. It visualizes configuration parameters and their settings, thus providing a means to illustrate and distinguish distinct pattern variants. The requirements for process flexibility are described by means of 34 process flexibility patterns based on five distinct flexibility types. These flexibility types distinguish the moment and the manner in which both foreseen and unforeseen behavior can be introduced into a process. In order to avoid potential ambiguities in regard to pattern interpretation, the semantics of all patterns are formally described in the terms of Colored Petri Nets (CPNs). This modeling technique is widely used throughout the thesis. In doing so, a set of commonly-used and recurrent constructs have been identified during the modeling of CPN diagrams. These constructs form the basis for a comprehensive CPN pattern language.