Task: Document Service Non-functional Requirements
Refine the service specifications to include the non-functional requirements that will impact the solution.
Disciplines: Architecture
Purpose

Document the Quality-of-Service requirements for the specified services.

Relationships
Main Description

Utilizing a Service-Oriented Architecture provides the opportunity for a service consumer to choose a service provider based not only on the functionality it provides, but also on the Qualities of Service (QoS) that it might guarantee.  Because of this, it is important to clearly specify the expected non-functional requirements required by a consumer.  When these requirements are known, the servicing organization can commit resources to create and maintain service components that deliver the necessary QoS.  Key architectural decisions might need to be made to ensure that the QoS can be delivered.

Steps
Document non-functional requirements

Identify from the system-wide requirements the non-functional requirements that consumers are likely to impose upon each service in the service model.  Such requirements could include, but are not limited to:

  • Availability. (Mean time between failure)
  • Operational window. (Is there ever a time when the service is not expected to be used?)
  • Response time. (How quickly does the service need to respond to a request?)
  • Peak throughput. (How many requests for the service can arrive per unit of time? Such as per second, per minute, per hour.)

Document any key architectural decisions that are needed to meet these requirements. These decisions also need to be reflected appropriately within the software architecture document.

The manner in which non-functional requirements are attached to the ServiceInterface is not defined by this guidance. Neither are there bounds set on what constitutes such a requirement. 

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