This chapter discusses the challenges associated with integrating work performed by human agents into automated workflows. It briefly recounts the evolution of business process support systems and concludes that although the support for people integration continues to evolve in these offerings, in broad terms it has not advanced markedly since their inception several decades ago. Nevertheless, people are an integral part of business processes and integration of human work deserves special consideration during process design and deployment. To this end, the chapter explores the requirements associated with modelling human integration and examines the support for people integration offered by WS-BPEL, which (together with its WS-BPEL4People and WS-HumanTask extensions) currently represents the state of the art when defining and implementing business processes in a service-oriented environment. In order to do this, it utilises a common framework for language assessment, the workflow resource patterns, both to illustrate the capabilities of WS-BPEL and to identify future technical opportunities.
2. Background Information Overview: Existing Technologies, Notations And Approaches
In this section we provide background information about the lifecycle of business processes. We also give an overview of the existing Semantic Web Service frameworks used to describe the semantics of services by means of ontologies as the underlying paradigm and motivate the need for the use of semantics in the context of BPM.
Key Terms in this Chapter
Human Role: The organizational or process-related role (or roles) that a human agent assumes in a particular business process. Roles are typically used as a grouping mechanism for individual agents with similar capabilities or responsibilities. They increase the flexibility of process definitions by providing a means of specifying work distribution that is independent of individual resources and allow individual work items to be directed suitable resources on a dynamic basis at runtime rather than requiring their identification in the design-time process model.
Work Distribution: The distribution of individual work items to agents in an organization based on both static criteria specified as part of the design-time process model and also on dynamic criteria (also contained in the process model) evaluated at runtime on the basis of the current process state, resource characteristics and preceding execution history.
Web Service Business Process Execution Language for People: A language extension for the Web Service Business Process Execution Language (WS-BPEL), an industry standard for the automation of business processes in a service-oriented environment. Initially, WS-BPEL lacked support for creating and scheduling tasks to be performed by human resources. This was perceived as a major impediment to its adoption in a broader context and an industry consortium formed to develop the Web Service Business Process Execution Language for People (WS-BPEL4People) proposal. The proposed extension standardizes the invocation and coordination of service-enabled human tasks (cf. Web Service Human Task) via a WS-BPEL process.
Workflow Resource Patterns: A comprehensive collection of patterns identifying desirable work distribution and resource management capabilities in workflow management systems. They are part of a larger framework that includes coverage of related workflow perspectives, such as control flow, data flow, and exception handling. The patterns are frequently used as a reference against which workflow systems, web service composition standards and business process modeling languages can be evaluated and compared.
Human Task: A defined unit of work undertaken by a human agent in the context of a business process. Human tasks typically relate to activities for which there is no potential or requirement for automation. Individual human tasks are often composed into workflows that document a broader organizational process and in doing so identify the division of labor between the various organizational agents and groups that undertake the constituent human tasks.
Web Service Human Task: A Web Service standard that is independent of, but often used in conjunction with, the Web Service Business Process Execution Language for People (WS-BPEL). Web Service Human Task (WS-HumanTask) defines a common metamodel for the description of human tasks and standardized interfaces as well as a coordination protocol for their invocation by Web Service clients. The standard thus facilitates the deployment of human task as services, enabling the reuse of existing business task management components in a service-oriented environment.
Service Enablement: An architectural paradigm that advocates the encapsulation of functions into reusable components by means of a platform-independent interface description language. Such components can be freely assembled into new solutions, promoting both the flexibility and reuse of existing IT assets.