Part electrical, mechanical and physical characteristics should
be defined in a device specification to be used for design and procurement.
Applicable device electrical performance parameters that ensure product
performance objectives are met for all operating conditions should be
specified, including reliability parameters. This information may be available
in vendor catalogs/data sheets. Special care should be taken for electrical
parameters that are "guaranteed but not tested," or other special features
which should be discussed and agreed to with each vendor. The part
specification should be based on several factors, including operating
environments, worst case stress levels, and quality requirements.
The Defense Electronic Supply Center (DESC) Standard
Microcircuit Drawing format is an example of how to prepare a company
specification for microcircuits and other applicable components. This format
has been reviewed and coordinated with industry and can be used to develop a
specification that provides realistic, clearly stated requirements. Details
are provided in MIL-HDBK-780 "Standardized Microcircuit Drawings." Reference 
“Analog Testing Handbook (ATH)” provides information for the specification for
analog and mixed mode (analog/digital) devices.