2Service design & transition

• 2.1SLA/OLA/UC & service-level design

  Covers the three-layer structure of the SLA agreed between provider and customer, the OLA between internal operations teams, and the UC (underpinning contract) with external suppliers, how SLM maintains and improves them, and how to design service-level targets amid trade-offs of availability, cost, and feasibility.

• 2.2Change management

  Covers choosing among three change paths—standard changes that are pre-approved and routine, normal changes assessed by the CAB, and emergency changes decided by the ECAB and documented afterward—and how to make changes to a live service safely through risk assessment and a back-out (rollback) plan.

• 2.3Release & deployment management

  Covers release and deployment management, which safely delivers approved changes to production: designing the release unit (what is packaged together), choosing a deployment approach such as phased rollout or a pilot, and how to plan distribution to a live service through the separation of build, test, and deploy.

• 2.4Configuration management

  Covers configuration management, which accurately manages the CIs (configuration items) that make up a service in the CMDB, its linkage with change management and release management, and how it differs from IT asset management, whose main purpose is grasping owned assets—all from the practical angle of impact analysis and maintaining accuracy.

• 2.5Designing availability & capacity (at design time)

  Covers how, at the design stage, to realize an availability target derived from requirements—redundant design that eliminates a single point of failure, series (product) and parallel (1−(1−a)ⁿ) availability, and designing capacity from a future demand forecast—all amid trade-offs with cost.