The Service Lifecycle comprises of 5 core stages; Service Strategy - Service Design - Service Transition - Service Operation - Continual Service Improvement.
Our diagram shows a flattened out version of the ITIL lifecycle, showing stages in a 'start to finish' fashion. There are several forms of the lifecycle model, with a circular model being the most common. The cog or wheel model reminds us that the lifecycle is constantly revolving and adapting to business change. In any case, it's important to remember that the lifecycle is non-linear and information flows freely between any of the stages to allow adaptation for service improvement.
Each of the ITIL stages (strategy, design, transition, operation, continual improvement) relies on principles, processes, roles and performance measures. Service Strategy is at the heart of the lifecycle, with Service Design, Transition and Operation following there after. Each of the stages is influenced from the inputs and feedback from the other stages.
Starting with the Service Strategy, we clarify and prioritize service-provider investments in services. From the strategy stage, we create outputs including strategies, policies and constraints which pass onto the Service Design phase.
During Service Design we start the actual designing of IT services, processes, and other aspects of the Service Management effort. From here we formulate the Service Design Package (SDP) capturing all the necessary information and attributes about our service. We also create the Service Catalogue which is usually a database or structured document containing information about all live services, including those available for deployment.
From Service Design, we pass over design documents to Service Transition, where the actual service(s) and value is directly delivered to customers. We also begin monitoring problems and considering the balance between service reliability and cost. If requirements or assumptions have changed since design, we can always make modifications during the Transition stage to deliver the required service.
The next stage, Service Operation, is at the heart of 'value'. It's where services actually deliver value to the business. During this stage, we aim to deliver agreed levels of service to users and customers, and also manage the applications, technology and infrastructure to support the service delivery.
The final stage of the ITIL lifecycle is the Continual Service Improvement phase. This is where we align and realign IT Services to changing business needs by identifying and implementing improvements that support the Business Processes. As you can see on the diagram above, it's a continual phase so we constantly aim to align and realign as the environment, business or customer conditions change.
The strength of the ITIL Service Lifecycle rests upon continual feedback throughout each stage. It's important to remember that the lifecycle is non linear and at every point in the lifecycle, monitoring, feedback and assessment flows freely. These drive decisions about need for corrections or change in the service.
See also:- Return on Investment (ROI)
- Policies
- SKMS
- Standards
- Architecture
- Design Plans
- Constraints