Project and Lifecycle Stages
The following represent common and primary stages (or phases) related to SOA projects and the overall service lifecycle:
Figure 1 – Common stages associated with SOA projects. Note the distinction between SOA project stages, service delivery project stages, and service lifecycle stages. These terms are used in the subsequent pages when referring to the overall adoption project, the delivery of individual services, and service-specific lifecycle stages, respectively.
Although Figure 1 displays stages sequentially, how and when each stage is carried out depends on the methodology being used. Different methodologies can be considered, depending on the nature and scope of the overall SOA project, the size and extent of standardization of the service inventory for which services are being delivered, and the manner in which tactical (short-term) requirements are being prioritized in relation to strategic (long-term) requirements.
A fundamental characteristic of SOA projects is that they tend to emphasize the need for some meaningful extent of strategic target state that the delivery of each service is intended to support. In order to realize this, some level of increased up-front analysis effort is generally necessary. Therefore, a primary way in which SOA project delivery methodologies differ is in how they position and prioritize analysis-related phases.
There are two primary analysis phases in a typical SOA project: the analysis of individual services in relation to business process automation, and the collective analysis of a service inventory. The Service-Oriented Analysis phase is dedicated to producing conceptual service definitions (service candidates) as part of the functional decomposition of business process logic. The Service Inventory Analysis establishes a cycle whereby the Service-Oriented Analysis process is carried out iteratively (together with other business processes) to whatever extent a top-down (strategic) approach is followed.
The upcoming sections briefly describe these and other stages.