Service-Oriented Design (Part IV: Business Process Design)

Service Oriented Design (Part IV Business Process Design)

The orchestration service layer provides a powerful means by which contemporary service-oriented solutions can realize some key benefits. The most significant contribution this sub-layer brings to SOA is an abstraction of logic and responsibility that alleviates underlying services from a number of design constraints.

For example, by abstracting business process logic:

• Application and business services can be freely designed to be process-agnostic and reusable.
• The process service assumes a greater degree of statefulness, thus further freeing other services from having to manage state.
• The business process logic is centralized in one location, as opposed to being distributed across and embedded within multiple services.

In this chapter we tackle the design of an orchestration layer by using the WS-BPEL language to create a business process definition.

 

How case studies are used: Our focus in this chapter is the TLS environment. We provide case study examples throughout the step-by-step process description during which TLS builds a WS-BPEL process definition for the Timesheet Submission Process. This is the same process for which service candidates were modeled in Chapter 12 and for which the Employee Service interface was designed in Chapter 15.