ITIL Foundation Primer Part 2: Service Composition

ITIL Service Composition Diagram


Definitions: Service Assets: Resources & Capabilities
Resource: IT equipment / infrastructure, people, money or anything else that helps to deliver the service. Resources are assets of the organisation.
Capability: The ability of a service organisation, person, process, application or IT service to carry out an activity. Capabilities are intangible assets such as management, organisation, process, knowledge and peoples skills.

The diagram above shows all the elements that come together to create an IT Service.  These are detailed below.

  1. Business Processes: Examples include Order Entry and Credit Checking
  2. Service: The service being delivered to customers for example Billing
  3. Service Design Package (SDP): A package of documents defining all aspects of a service and its requirements through each stage of its lifecycle.
  4. Business Case: The justification for the service investments and expenditure
  5. Service Level Agreements (SLAs) and Service Level Requirements (SLRs): Set out the level, scope and quality of the service that is to be provided.
  6. Infrastructure: All the IT equipment required to deliver the service.
  7. Environment: When the IT equipment is securely implemented, typically data centres, machine rooms, power, cooling etc.
  8. Data: The data required to provide the service. For example customer records, product records, supplier details etc
  9. Applications:  All the software required to process the data to provide the information required by the business process for example ERP packages, CRM packages etc.
  10. Integration: Solutions to integrate/combine data from different sources.
  11. Operational Level Agreements (OLAs) and Contracts: Any underpinning agreements required to deliver the service within the SLA.
  12. Supporting Services: Any services required to deliver this service – e.g. Networking.
  13. IT Processes: The processes needed by the service provider to ensure the successful delivery of the service for example Service Desk Management, Change Management, Availability Management, Monitoring etc.
  14. Functions: Any internal teams providing support for any of the components required to provide the service, for example Service Desk.
  15. Roles: Responsibilities, activities, authorities granted to a person or team that control and deploy the resources engaged in the service. For example Problem Managers, Release Managers, Capacity Managers and Service Owners.
  16. Suppliers: Any external third parties necessary to provide the service. For example the Internet Service Provider would be a key supplier for a Web Service.

Google Service Status Page – A great example of best practice.

Following the brief outage of gMail on September 1st I was reminded that Google publish a status page or dashboard showing the status of all their services.  You can find this service at  I mention this because it’s an excellent example of providing visibility and therefore accountability about the services you are providing which is essential if you’re being paid to provide a service.  If you’re responsible for providing various IT services to your business or customers then you really need to consider how you can create this type of service dashboard or status page.

If you’re involved in providing online services then you need to have formally agreed service up-time levels and planned maintenance times.  When agreeing up-time SLA’s you need to get people to understand the cost of moving from 98% to 99%, to 99.99% to 99.999% (five nines) up-time.  Have a think about it, the level of engineering needed to deliver 99% is quite different to 99.999%.

Availabilityper dayper monthper year

If you commit to 99.999% up-time, you’re allowed 5 minutes a year, that’s not enough time to do anything so you need to your application to be running on a distributed system over two or more sites with instant fail over and probably load balanced workload.   In contrast 99% up time allows you 87 minutes of downtime which means that you can stick with simpler technologies like RAID and mirrored servers.

Let me know what you think and how you approach up-time SLA’s.