Even with the best planning, monitoring, and delivery of services, unintended events can occur that are unwanted. Some instances of service delivery can have lower than expected or lower than acceptable degrees of performance or quality, or can be completely unsuccessful. The CMMI-SVC model refers to these difficulties as “service incidents.” The glossary defines a “service incident” as an indication of an actual or potential interference with a service. The single word “incident” is used in place of “service incident” when the context makes the meaning clear.

Like requests, incidents require some recognition and response by the service provider; but unlike requests, incidents are unintended events, although some types of incidents can be anticipated. Whether or not they are anticipated, incidents must be resolved in some way by the service provider. In some service types and service provider organizations, service requests and incidents are both managed and resolved through common processes, staff, and tools. The CMMI-SVC model is compatible with this kind of approach, but does not require it, as it is not appropriate for all types of services.

The use of the word “potential” in the definition of service incident is deliberate and significant; it means that incidents do not always involve actual interference with or failure of service delivery. Indications that a service may have been insufficient or unsuccessful are also incidents, as are indications that it may be insufficient or unsuccessful in the future. (Customer complaints are an almost universal example of this type of incident because they are always indications that service delivery may have been inadequate.) This aspect of incidents is often overlooked, but it is important: failure to address and resolve potential interference with services is likely to lead eventually to actual interference, and possibly to a failure to satisfy service agreements.