Planning a service model

A service model defines the various resources that deliver business services, models their behaviors and functional relationships, and manages the delivery of the resulting services. Designing and building a robust service model enables you to view and change the relationships between the different components in the model, as well as add new components to the model.

Relationships between service components

A physical or logical resource represented in the model is known as a service component instance or component instance. The functional relationship between two resources (component instances) is called a service component relationship or a relationship. These concepts are illustrated in the following figure.

 Service model objects

For example, Calbro Services uses an online banking application that supports its customers' ability to access accounts and complete transactions. The relationship between these two items (the online banking application and the actual banking service) is part of the service model.

A service model that relates business services to IT enables IT to pinpoint root causes and prioritize business-critical problems. Understanding what a service is and how it delivers value to the business is the foundation for Service Transition, an ITIL process. In ITIL version 3, IT processes are part of the service lifecycle and IT services are viewed as business assets. The online store depicted in the following figure illustrates that IT is a business asset because the online checkout is only as good as the physical server on which the checkout software resides, or the software itself. If either the hardware or software fails, the user cannot complete his purchase.

CI and relationship addition to service models using BMC CMDB

BMC CMDB is a possible source for service model objects that are used by BMC Service Impact Manager (BMC SIM) and other BSM applications. Understanding service models in general can help you as you plan, populate, and work in BMC CMDB. Typically, objects used by BMC SIM are discovered using discovery tools. They are reconciled by the BMC CMDB Reconciliation Engine, and then automatically published to the BMC Impact Manager by using BMC Impact Publishing Server.

You can also use CMDB Explorer to create relationships between CIs for special cases, such as when you have two configuration items (CIs) that were created manually through Explorer. You can use this method for creating business assets like business service objects and organization objects.

You can use Impact Simulator whether you use BMC SIM in your environment or not. The Impact Simulator predicts the impact on CIs by using the impact relationships that you configure within BMC CMDB. Impact Simulator can also use the impact relationships configured with BMC Service Impact Manager.

For more information about service models as used in BMC Service Impact Manager, see the BMC Impact Solutions: Service Model Administrator's Guide. For more information about Impact Simulator, see Simulating the impact of changes to CIs.

View service model components

To support a service model that complies with ITIL, BMC CMDB includes several components that combine the utility (what a service does) and warranty (how the service is delivered). The following figure shows a high-level view of these components.

 Service model components 

• Service — Describes functionality that an organization provides. In BMC CMDB, the service is a container that includes service and requestable offerings and service level targets.
  • Business service — Services available to customers that show the consumer view of services, such as email or an online store.
  • Technical service — Supporting IT and infrastructure resources required to support business services that are not visible to customers, such as servers, applications, and network configuration items (CIs). These technical services can be associated in Explorer with CI queries.
• Service offering — Defines what service an organization provides and how it is provided. A service offering defines a level of service for a price; it combines the service (utility) and a service level target (warranty), and add-on options to bring value to the customer. All technical and business services must have at least one service offering. However, a service can have more than one service offering. You can also associate a service offering with a technical service.
• Requestable offering — Defines what service an organization provides and how it is provided. However, unlike service offering, end users can see and select a requestable offering. The requestable offerings provide options for how IT implements the service offering. Each requestable offering defines a level of service for a price: it combines the service (utility), a service level target (warranty), and add-on options.
• Service level target — Describes measurements for the performance of a service or offering.
• Options — Describes discrete choices that customers can select. for a service, requestable offering, and transactional offering. Each option has one or more choices, each of which has cost and price information. These options and their choices are available for users to select. They are managed separately from offerings because they do not rely on a specific offering, making the options reusable.

Best practices for defining a service model

Defining the service model involves establishing a list of all the IT resources that should be represented in the service model. This information should include the following items:

• Each resource's name or component identification pattern
• Its location or site

Use this information later in the design phase and when creating service model components.

The first step in developing a service model is to design its logical architecture. To do this, you must analyze the IT environment to:

• Identify the resources that make up the service model.
• Determine the functional relationships and dependencies between various resources that can affect services.

Related topics

Administering service models and the Service Catalog

Working with CIs and relationships