Requirements

Common requirements like validity, completeness, consistency or unambiguity must be fulfilled by all types of contracts. But there are additional requirements for service level agreements that specify complex IT services in a long-term customer-provider relationship. A service level agreement must be:

customer-centric:

The SLA must be specified in a terminology originating from the customer's usage scenario. The service implementation should be transparent to the customer. The service may not use the terms of the service implementation view usually preferred by the provider. But this must not lead to restricted expressiveness. All necessary details must be expressible while allowing the abstraction of well known facts.

This results in a service-oriented description which does not restrict the implementation of the service by the provider allowing to profit from technological progress. If a SLA is demanding a special kind of implementation a new SLA must be negotiated to make use of possible advantages. Instead it should focus on usage processes.

constructive:

Management facilities for the customer are an essential element in a SLA. The management interactions should be used to actively prevent or at least constructively solve problems in cooperation. Operators as well as users should be guided to become active by a service level agreement if the situation requires intervention. The SLA must define the rights and duties of both, customer and provider. All other management interactions like ordering, accounting, maintenance, etc. need to be explicitly specified, too.

As for service functionality there also must be service levels for the management processes. The service level must be specified by concrete quality criteria which are measurable and realistic. The SLA must be understandable by both, user and operator. Therefore, a SLA requires concrete and workable instructions which are supportive for usage and management. This way the service level agreement is present during operation and usage not just in a legal proceeding.

Summarizing, to reach these targets a constructive SLA is needed which is customer-centric and service-oriented. Furthermore, it must be concrete, understandable and workable, but without loosing expressiveness. That means all contracting partners know their rights and their duties.