Requirements Gathering What are requirements A requirement is

Requirements Gathering

What are requirements? • A requirement is a statement about an intended product that specifies what it should do or how it should perform. • Aim to make the requirements as specific, unambiguous, and clear as possible. • How will you know when a requirement has been fulfilled?

Kinds of Requirements • Functional requirements – say what the system should do. • Non-functional requirements – identify constraints on the system and its development. • Example: must be able to run on a variety of platforms such as …. • Data requirements – capture the type, volatility, size/amount, persistence, accuracy, and value of the required data

Kinds of Requirements • Environmental requirements or context of use – circumstances in which the product will be expected to operate. • Physical environment to include lighting, noise, and dust • Social environment – collaboration and coordination • Organizational environment – how good is user support likely to be, training needed, • Technical environment – what technologies will product run on; what technological limitations might be relevant?

Kinds of Requirements • User characteristics – key attributes of the intended user group. This includes user’s abilities and skills. • • • Novice An expert A casual user A frequent user Users’ nationality Educational background Physical or mental disabilities – accessibility requirements This affects the ways in which interaction is designed. The user profile or profiles?

Data gathering for requirements • Find out about the task that users currently perform and their associated goals • The context in which tasks are performed • Rationale for the current situation • Common forms of data gathering: • • • Interviews Focus groups Questionnaires Observation Study documentation Research similar products since they have established requirements • It is important to meet stakeholders and for users to feel involved.

Data Recording • Take notes • Develop interview questions • Develop format for requirements documentation

Data analysis, interpretation, and presentation • • • Volere shell for requirements Data-flow diagrams State charts Work-flow charts Entity-relationship diagrams Use cases