A design specification document (DSD)is a detailed document which provides information about a designed product or process. For example, the design specification must include all necessary drawings, dimensions, environmental factors, ergonomic factors, aesthetic factors, maintenance that will be needed, etc. It may also give specific examples of how the design should be executed, helping others work properly. Advantages include, DSD gives a proper idea about how the product become. Disadvantage includes, high detailed specification is provided which is sometimes not required. A design input document (DID) gives the basic desire for the product. It is a broad type of document. Whole team of the organization gives the input also the customers gives the input. Market and customer desires are taken into account. The design input requirement is documented and reviewed and approved by a designated individual. Advantage includes DID are build upon the user needs and intended use. It makes sure that design input is clear and objective. Disadvantage includes, it does not provide specific description so designing the product becomes difficult.