– A use case is a description of a system’s behaviour as it responds to a request that originates from outside of that system. Use cases describe the interaction between a primary actor—the initiator of the interaction—and the system itself, represented as a sequence of simple steps. Actors are something or someone which exist outside the system under study, and that take part in a sequence of activities in a dialogue with the system, to achieve some goal: they may be end users, other systems, or hardware devices. Each use case is a complete series of events, described from the point of view of the actor
– A Business analysis provide typical deliverables. Business Requirements are a specification of what the business wants. This is usually expressed in terms of broad outcomes the business requires, rather than specific functions the system may perform.
- Functional requirements. It describes what the system, process, or product/service must do in order to fulfill the business requirement(s). Note that the business requirement often can be broken up into sub-business requirements and many functional requirements. These are often referred to as System Requirements.
- Non-Functional requirements, which cannot be met by a specific function (e.g. performance, scalability, security and usability requirements). These are often included within the System Requirements, where applicable.
- Put another way, thanks to 3SL featuring an interesting page on Non-Functional requirements,
User requirements are statements of user need, as expressed by the groups of stakeholders concerned with the system being developed.
– ISO 9126, international standard for the evaluation of software quality.