Introduction

  The increasing dependence of a companies success on IT infrastructures requires to face the challenges of service quality. The complexity of the needed IT services is growing. Therefore, the design and operation of services is often outsourced to independent internal departments or to external partners.

To specify the requested service customer and provider sign a service level agreement (SLA). Such SLAs define the functionality of the service and the required service level. The SLA is an important source of information for the provider's service management because the service provider often does not know much about the scenario the service is used in. Thus, the quality of the SLA is one important parameter for the success of outsourcing relationships.

Keeping the service quality on a reasonable level is the challenge of modern services. It is also a task of service level agreements to ensure that the customer has sufficient management facilities to monitor and control the actual service quality. Therefore, management interactions need to be specified in addition to service level and functionality. Most SLAs focus on technical parameters of the service like bandwidth or availability. But the management interactions must also fulfill quality criteria. In this paper the term management means the service management crossing the domain boundary between customer and provider. Management of the service implementation done by the provider is considered as operation.

The specification of interactions is difficult if it is only based on a relatively informal collection of rules and statements. The temporal aspect of interaction processes cannot be represented adequately and it is hard to master the complexity with unstructured methods from which many SLAs for today's IT services result.

Each interaction can be seen as a process. Production processes or business processes are described by workflow concepts. Therefore, this paper proposes the usage of workflow concepts for designing and writing of high quality service level agreements for IT services. For demonstrating purposes a scenario is presented in section . Sections defines the term service level agreement, derives requirements and identifies the elements of SLAs. The relevant concepts of workflow modeling are described in section . Section presents our process model for use in service level agreements followed by the classification of processes. Section shows a simplified example process to demonstrate the application of our approach. The last section draws a conclusion and introduces future work.