role-based interaction of people provides means of assigning users to generic human roles takes care to delegate ownership of a task to a person only supports scenario as four-eyes scenario nomination escalation chained execution by extending BPEL with additional independent syntax and semantic. The WS-HumanTask specification introduces the definition of human tasks and notifications, including their properties, behavior and a set of operations used to manipulate human tasks. A coordination protocol is introduced in order to control autonomy and life cycle of service-enabled human tasks in an interoperable manner. The BPEL4People specification introduces a WS-BPEL extension to address human interactions in WS-BPEL as a first-class citizen. It defines a new type of basic activity which uses human tasks as an implementation, and allows specifying tasks local to a process or use tasks defined outside of the process definition. This extension is based on the WS-HumanTask specification. WS-BPEL 2.0 Version 2.0 introduced some changes and new features: New activity types: repeatUntil, validate, forEach (parallel and sequential), rethrow, extensionActivity, compensateScope Renamed activities: switch/case renamed to if/else, terminate renamed to exit Termination Handler added to scope activities to provide explicit behavior for termination Variable initialization XSLT for variable transformations (New XPath extension function bpws:doXslTransform) XPath access to variable data (XPath variable syntax $variable[.part]/location) XML schema variables in Web service activities (for WS-I doc/lit style service interactions) Locally declared messageExchange (internal correlation of receive and reply activities) Clarification of Abstract Processes (syntax and semantics) Enable expression language overrides at each activity See also BPEL4People BPELscript Business Process Model and Notation Business Process Modeling List of BPEL engines Web Services Conversation Language Workflow WS-CDL XML Process Definition Language Yet Another Workflow Language References Further reading Books on BPEL 2.0 SOA for the Business Developer: Concepts, BPEL, and SCA. XML-based standards Web service specifications Workflow languages