A service is delivered through the operation of a service system, which the glossary defines as an integrated and interdependent combination of component resources that satisfies service requirements. The use of the word “system” in “service system” can suggest to some that service systems are a variety of information technology, and that they must have hardware, software, and other conventional IT components. This interpretation is too restrictive. While it is possible for some components of a service system to be implemented with information technology, it is also possible to have a service system that uses little or no information technology at all.

In this context, the word “system” should be interpreted in the broader sense of “a regularly interacting or interdependent group of items forming a unified whole,” a typical dictionary definition. Also, systems created by people usually have an intended unifying purpose, as well as a capability to operate or behave in intended ways. Consider a package delivery system, a health care system, or an education system as examples of service systems with a wide variety of integrated and interdependent component resources.

Some users may still have trouble with this interpretation because they may think that the way they deliver services is not systematic, does not involve identifiable “components,” or is too small or difficult to view through the lens of a systems perspective. While this difficulty can in some cases be true for service provider organizations with relatively immature practices, part of the difficulty can also be traced to an overly narrow interpretation of the word “resources” in the definition of service system.

The full extent of a service system encompasses everything required for service delivery, including work products, processes, tools, facilities, consumable items, and human resources. Some of these resources can belong to customers or suppliers, and some can be transient (in the sense that they are only part of the service system for a limited time). But all of these resources become part of a service system if they are needed in some way to enable service delivery.

Because of this broad range of included resource types and the relationships among them, a service system can be something large and complex, with extensive facilities and tangible components (e.g., a service system for health care, a service system for transportation). Alternatively, a service system could be something consisting primarily of people and processes (e.g., for an independent verification and validation service). Since every service provider organization using the CMMI-SVC model must have at a minimum both people and process resources, they should be able to apply the service system concept successfully.

Service providers who are not used to thinking of their methods, tools, and staff for service delivery from a broad systems perspective can need to expend some effort to reframe their concept of service delivery to accommodate this perspective. The benefits of doing so are great, however, because critical and otherwise unnoticed resources and dependencies between resources will become visible for the first time. This insight will enable the service provider organization to effectively improve its operations over time without being caught by surprises or wasting resources on incompletely addressing a problem.