Cooperation Patterns and Adaptation Patterns for Service-Based Inter-Organizational Workflows

Overview & Synopsis

Modernization is an effective approach to making existing mainframe and distributed systems more responsive to business needs. SOA (service-oriented architecture) is an adequate paradigm that allows companies to tap into the business value in their current systems and position IT for rapid future changes to the business model. In our research works, we focus on the use of SOA to implement Inter- Organizational WorkFlows (IOWF). The goal is to take benefits from the advantages offered by the SOA paradigm like interoperability, reusability and flexibility in order to deal with workflow models easily adaptable, evolvable and reusable. This paper focuses on two specific architectures of IOWF which are the "chained execution" and the "subcontracting"; the first issue of this work is to define Service-Based Cooperation Patterns (SBCP) suitable to the two architectures considered. A SBCP is based on SOA; it is defined through three main dimensions: the distribution of services among the partner's sites, the control of instance execution and the structure of interaction between the workflows involved in the cooperation. The second issue of the paper consists of adaptation and evolution of IOWF process models obeying to the defined SBCP. Then, we state the main operations of adaptation that can be applied on these models; we focus on adaptation at process and interactional levels. Conformably to the three dimensions of SBCP, we define three classes of adaptation patterns: "service adaptation", "control flow adaptation" and "interaction adaptation" patterns. Also, we particularly distinguish some operations of adaptation called evolution of process models based on two perspectives: the expansion of the global functionality of the process and the expansion of the cooperation; we show that some evolutions are realized by reuse of existing IOWF models. For implementation, we consider IOWF process models specified with BPEL.