Abstract
From an economic point of view, web services are gaining momentum in the so‐called network economics. Service composition, or service‐based workflow, offers enhanced reusability, agility, and dynamicity. Many resources including data, computational resources, and others are wrapped with service interfaces to enable uniform access. Workflow systems are increasingly being developed to allow users to integrate, orchestrate, and monitor various local or remote service resources to perform tasks like transaction processing, batch job execution, and scientific discovery. This chapter uses web service and service interchangeably, and service workflow and service composition interchangeably. It summarizes the research of workflow in service oriented computing (SOC) into five topics, that is, languages for service composition, automatic service composition, mediation‐aided service composition, verification of service workflow, and decentralized execution of workflow. The chapter discusses some of the issues in evolving IT environment: social network meets service computing and practical and flexible service composition.