需求( Requirements) [IEEE Standard Glossary of Software Engineering 1990] (1)a condition or capability needed by a user to solve a problem or achieve an (2) A condition or capability that must be met or possessed by a system or system component to satisfy a contract, standard, specification, or other omall pseudocumene. (3)A documented r 开发者的角度一一系统的内部特性什么是需求？ 需求（Requirements ） [IEEE Standard Glossary of Software Engineering 1990]: (1)A condition or capability needed by a user to solve a problem or achieve an objective. (2)A condition or capability that must be met or possessed by a system or system component to satisfy a contract, standard, specification, or other formally imposed documents. (3)A documented representation of a condition or capability as in (1) or (2) 开发者的角度——系统的内部特性