United States Military Standard

A United States defense standard, often called a military standard, "MIL-STD", "MIL-SPEC", or (informally) "MilSpecs", is used to help achieve standardization objectives by the U.S. Department of Defense.

Standardization is beneficial in achieving interoperability, ensuring products meet certain requirements, commonality, reliability, total cost of ownership, compatibility with logistics systems, and similar defense-related objectives [1].

Defense standards are also used by other non-defense government organizations, technical organizations, and industry. This article discusses definitions, history, and usage of defense standards. Related documents, such as defense handbooks and defense specifications, are also addressed.

Although the official definitions differentiate between several types of documents, all of these documents go by the general rubric of "military standard", including defense specifications, handbooks, and standards. Strictly speaking, these documents serve different purposes. According to the Government Accountability Office (GAO), military specifications "describe the physical and/or operational characteristics of a product", while military standards "detail the processes and materials to be used to make the product." Military handbooks, on the other hand, are primarily sources of compiled information and/or guidance. The GAO acknowledges, however, that the terms are often used interchangeably.

Official definitions are provided by DoD 4120.24-M, [2], Defense Standardization Program (DSP) Policies and Procedures, March 2000, OUSD (Acquisition, Technology and Logistics):

For purposes of this article, "defense standards" will include standards, specifications and handbooks.

The DOD has standards about the format of standards:

Defense standards evolved from the need to ensure proper performance, maintainability and reparability (ease of MRO), and logistical usefulness of military equipment. The latter two goals (MRO and logistics) favor certain general concepts, such as interchangeability, standardization (of equipment and processes, in general), cataloguing, communications, and training (to teach people what is standardized, what is at their discretion, and the details of the standards). In the late 18th century and throughout the 19th, the American and French militaries were early adopters and longtime developmental sponsors and advocates of interchangeability and standardization. By World War II (1939-1945), virtually all national militaries and trans-national alliances of the same (Allied Forces, Axis powers) were busy standardizing and cataloguing. The U.S. AN- cataloguing system (Army-Navy) and the British Defence Standards (DEF-STAN) provide examples.

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