Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A functional specification (also, functional spec, specs, functional specifications document (FSD), or Program specification) in systems engineering and software development is the documentation that describes the requested behavior of an engineering system. The documentation typically describes what is needed by the system user as well as requested properties of inputs and outputs (e.g. of the software system).

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.