What is an SMD?

A Standard Microcircuit Drawing (SMD) is a document that depicts the Government's requirements for an existing commercial microcircuit, tested for a military application. An SMD discloses applicable configuration, envelope dimensions, mounting and mating dimensions, interface dimensional characteristics, specified performance requirements, and inspection and acceptance test requirements as appropriate for a military environment.

Purpose of the SMD program:

The purpose of the SMD program is to prevent the proliferation of contractor-developed drawings describing generic microcircuits as if they were program-unique devices. SMDs cover off-the-shelf high-reliability microcircuits targeted for military applications, using only one standardized document. The SMD program increases the manufacturing base for DoD procurement and provides substantial savings in both acquisition and logistics.

History of the program:

In the early 1970's the only means of procuring standardized military microcircuits was through the Joint Army Navy (JAN) program, which was based on a general specification (MIL-M-38510), a test method standard (MIL-STD-883), and a qualified products list (QPL-38510). The JAN program provided highly reliable microcircuits for use in the harsh environments of military weapon systems and spacecraft.

Under the JAN program, standardization candidates were identified via NonStandard Part Approval Requests (NSPARs) received by the Military Parts Control Advisory Group (MPCAG). Detailed MIL-M-38510 "slash sheets" for individual devices were prepared and coordinated with device manufacturers and industry and military users. Once the slash sheets were completed, potential suppliers were audited and listed as qualified sources in QPL-38510.

Although this program provided microcircuits of the highest quality and reliability, it lacked the timeliness necessary for the design and production of high-tech weapon systems. The time from initiation of a specification project to the listing of a qualified source was typically two years.

With the increasing growth rate of technology, and the demand for weapon systems using the "latest and greatest" technology, Original Equipment Manufacturers (OEMs) did not always have the luxury of waiting for the JAN program to provide QPL-listed military devices; as a result, OEMs purchased off-the-shelf devices, as described by the device manufacturers' catalogs.

In order to provide technical documentation for these devices, OEMs prepared their own Specification Control Drawings (SCDs) or Source Control Drawings (SoCDs). This approach created a number of problems within the DoD logistics system.

With multiple OEMs independently preparing documentation for the exact same devices, the DoD logistics system was flooded with duplicate documentation. Many of these drawings incorrectly identified the devices as program-unique, resulting in duplicate stock in the DoD inventory.

The degree to which these drawings accurately described the testing requirements for the devices, and the degree to which device manufacturers reviewed and agreed to them, varied widely; consequently, many of these drawings fell far short of their goal of providing configuration control (i.e., ensuring reprocurement of interchangeable items).

In 1976 the Defense Electronics Supply Center (DESC) implemented the DESC Drawing Program. DESC Drawings were essentially government-prepared SCDs designed to combat the proliferation of duplicate OEM-prepared SCDs. DESC Drawings were available for use by all OEMs and government agencies, thereby eliminating the need for OEMs to prepare their own drawings, and reducing the duplication in the DoD logistics system.

A DESC drawing could be completed much faster than a JAN specification, and provided an interim procurement vehicle that could be used until a qualified MIL-M-38510 device was available; in addition, DESC Drawings were coordinated with device manufacturers, and Engineering Change Proposals (ECPs) were issued prior to significant drawing changes, providing for a level of configuration control not possible with OEM-prepared SCDs.

DESC Drawings were first used in 1976 by General Dynamics in the production of the F-16 aircraft. The program was successful in providing an alternative to SCDs, and continued to gain acceptance from the defense community into the early 1980's. By this time, DESC Drawings had begun to show promise as a viable alternative to the MIL-M-38510 specifications, rather than just an interim solution; however, many OEMs continued to use their own SCDs, in an effort to exercise some "control" over the configuration of devices used in their equipment.

In 1985, a number of military system failures underscored the inability of OEM-prepared drawings to provide reliably tested and standardized microcircuits; as a result, the OEMs requested that DoD implement a rapid-response single drawing program. The OEMs, device manufacturers, military services, and DoD representatives formed a Planning and Implementation (P&I) team to address this issue.

On the recommendation of the P&I team, the Secretary of Defense announced a 1 Oct 1986 implementation date for a Standardized Military Drawing (SMD) program for microcircuits, based on the existing DESC Drawing program. In early 1987, the Assistant Secretary of Defense for Production Support directed the military services and DoD agencies to implement all the necessary changes to contractual requirements by 1 Oct 1987.

In compliance with this new policy, SMD-specific requirements were added to such documents as MIL-STD-100, Military Engineering Drawing Practices; MIL-STD-965, Parts Control Program; and the Federal Acquisition Regulation 34.005.10.

Today SMDs are widely used throughout the defense community and remain the most efficient, cost-effective vehicle for procuring and supporting high-reliability microcircuits for military applications.

Significant milestones: