Ch. 4 Requirements Engineering

What are software requirements?

• The process of establishing the services that the customer requires from a system and the constraints under which it operates and is developed.

• Requirements can be functional or non-functional.

What are functional requirements?

• Requirements that describe system services or functions.

• Services the system should provide.

What are non-functional requirements?

• Requirements that are a constraint on the system or on the developmental process.

• Constrains on the services of functions offered by the system. E.g. speed, time to market

What is a requirement?

Can range from a high-level abstract statement of a service or of a system constraint to a detailed mathematical functional specification.
* Functions may serve as a dual function.

What are the two types of requirements?

• System requirements

• Software specification

What are system requirements?

A structured document setting out detailed descriptions of the system services. Written as a contract between client and contractor.

What are software specifications?

A detailed software description which can serve as a basis for a design or implementation. Written for developers.

Who are the ‘user requirement’ targets?

• Client managers

• System end-users

• Contract managers

• System architects

Who are the ‘system requirement’ targets?

• System end-users

• Client engineers

• System architects

• Software developers

Who are the ‘software specification’ targets?

• Client engineers

• System architects

• Software developers

What is a domain requirement?

Related to the application domain of the system (may be functional or non-functional requirements)