Requirement engineering

• The process of establishing the services that the customer requires from a system and the constraints under which it operates and is developed
• Row requirements need to be categorized in:
• Functional requirements describe system services functions\
• Non functional requirements is a constraints on the system or on the development process
• It may range from a high level abstract statement of a service or of a system constraint to a detailed mathematical functional specification
• This is inevitable as requirements may serve a dual function
• May be the basis for a bid for a contract - therefore must be open to interpretation
• May be the basis for the contract itself therefore must be defined in detail
• both these statements may be called requirement