Building the Service

Figure 4.1 shows how a service consists of constituent parts, all of which have to be considered during the design stage.

FIGURE 4.1 Service composition

Based on Cabinet Office ITIL® material. Reproduced under license from the Cabinet Office.

Services are composed of the following:

• The business processes that the IT service is going to support need to be understood if the design is to deliver what is required.
• The designer must ensure that the service being designed fulfills all the utility requirements—removing constraints or enhancing performance—in addition to abiding by any governance or reporting requirements and ensuring the service is in line with the organization’s strategic goals.
• As we discuss in Chapter 5, “Service Level Management: Aligning IT with Business Requirements,” the service level requirements for the new or changed service must be understood, and the necessary service level agreements and supporting agreements with support teams and suppliers need to be put in place.
• The designer must specify all the technical components of the service, using the configuration management system to show how these are linked to provide the service. The CMS is described in Chapter 9. The environmental aspects of the technical design must be documented, so that the operations management function understands what is required in terms of power, air conditioning, and so on.
• The applications that will provide the functional requirements of the business process and the data they require will also form part of the overall design specification.
• It is essential to understand what other services support the new or changed service; defining these dependencies will be done using the CMS, and service level management and supplier management will ensure that these supporting services deliver the level of service required.
• Finally, the service management processes that support the service must be documented and communicated to those who need to follow them.

Only when all these requirements are met and the interdependencies between them are understood and documented can there be confidence that the service will work as designed and deliver the benefits required.