Ontology-guided service-oriented architecture composition to support complex and tailorable process definitions

Services as abstractions of functionality have enabled the engineering of systems that support well-defined processes with relative ease. This success leads to aspirations for achieving greater complexity with the service-oriented paradigm. In particular, we address the case where the process definition is tailored differently in each instantiation based on negotiations among stakeholders of a socio-technical context. For such cases the process definition invariably crosscuts the architecture of a process-support system that composes available services. However, use of pre-defined process variations may bias the tailoring effort and thus, act against the original motivation of having a flexible definition. On the other hand, the characteristics of process complexity and tailorability introduce differences between stakeholder understanding of the process activities and their manifestation in tool support. We encounter these issues while developing a service-oriented process-support system for a security Certification and Accreditation (C&A) process. In this paper, we present our approach to effectively separate the C&A process definition from the architecture of its process-support system. We employ ontological modeling techniques to explicitly model the process definition and later expose it as a service to provide weaving rules for dynamically composing the process-support system architecture at runtime. The feasibility of our approach has been demonstrated in the design of a service-oriented architecture for a prototype workbench that supports the Department of Defense Certification and Accreditation Process (DITSCAP).