What are examples of functional, performance, essential physical characteristic, and detailed design-oriented specifications?
A18 A functional specification is the broadest possible definition of the Government’s minimum requirements, describing the work requirement solely in terms of the Government’s ultimate objective (i.e., what should the product do?). A functional specification does not mandate an approach to be used by the contractor. Consider the ‘cross the river’ example. The Government may require the contractor to provide a means to get a given mix and amount of traffic across the river. It is a functional specification, because the contractor selects the means (bridge, ferry, causeway, maybe even waders for pedestrians). If the Government specifies a bridge to carry that mix and amount of traffic, but leaves the details to the contractor (suspension or draw, stone or steel, two-lane or four) the specification is a performance specification. If the Government specifies that it needs a bridge and further specifies interface requirements and known customer preferences, e.g. gray, steel, drawbridge mee
