Since ancient history, defense standards had been established covering the whole spectrum of military operations (standardized formations – tactics) and defense materiel (spheres, shields, body armor etc.). There is plethora of ancient civilizations (Greeks, Egyptians, Romans etc) developed famous defense standards for military use.

A very famous example of an ancient Greek defense standard was developed for the sarisa or sarissa, a long spear about 4–6 meters (13–20 ft) in length. It was introduced by Philip II of Macedon and was used in his Macedonian phalanxes as a replacement for the earlier dory which was considerably shorter. These longer spears improved the traditional strength of the phalanx by extending the rows of overlapping weapons projecting towards the enemy, and the word remained in use throughout the Byzantine years to sometimes describe the long spears of their own infantry.

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[1], standardization (of equipment and processes, in general), cataloging, 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.

For example, due to differences in dimensional tolerances, in World War II American screws, bolts and nuts did not fit British equipment properly and were not fully interchangeable. Defense standards provide many benefits, such as minimizing the number of types of ammunition, ensuring compatibility of tools, and ensuring quality during production of military equipment. This results, for example, in ammunition and food cases that can be opened without tools; vehicle subsystems that can be quickly swapped into the place of damaged ones; and small arms and artillery that are less likely to find themselves with an excess of ammunition that does not fit and a lack of ammo that does.

The challenges associated with defense standardization and especially armaments standardization have been clear for many decades despite the stated benefits of enhanced armaments standardization. Calculating the benefits of armaments standardization is not easy and the closest there is to a scientific calculation is contained in a European’s Commission tendered report (the so-called ‘Sussex Study’) which calculated that armaments standardization could lead to cost savings of up to 50 %.

Nevertheless, figures that have been made available tend to stress the capability payoffs of standardization. For example, in 1992 Matthews reported that one former General from the US military claimed that a lack of armaments standardization in NATO has resulted in a 30 %-50 % reduction in the capability of the alliance.

The standardization of weapons systems is an increasingly important aspect of armaments standardization, especially in a context in which ‘system of systems’ architectures are now being developed. Indeed, the battlespace is increasingly defined by adversaries being able to rapidly integrate different technologies and systems into existing platforms.

Civil as Possible, Military only if necessary

Furthermore, without calculating the exact cost efficiency of standardization it has been implied by certain institutions that using civil standards could have a cost efficiency payoff for the defense sector. For example, in documenting the potential crossover from the civil sector to the defense sector it has been estimated that ‘up to 90 % of standards in the civilian naval sector could be used in the defense sector, as well as 75 % of those used in the aeronautic and 70 % in the land sectors’. Estimations on product cost savings following a more intensive use of civil standards by the military sector range from 10% up to 50%.


Defense Standardization Definitions

Defense Standards are covering operational (tactics, techniques, procedures), administrative (terminology) and materiel (ammunitions, fuels, systems and sub-systems, weapons etc). However there is plethora of definitions worldwide as depicted below.


North Atlantic Treaty Organization (NATO)

NATO is considered as the unique International Defense Standards Developing Organization and the major stakeholder on defense standardization internationally.

As defined in AAP-03[2], NATO standardization is the development and implementation of procedures, designs and terminology to the level necessary for the interoperability required by Allies, or to recommend useful practices in multinational cooperation.

The agreement, made voluntarily by NATO Allies to implement standards on a wide array of subjects, ranging from materiel to doctrine, provides the substantive glue which binds together the Alliance along with partner nations. 

A brief analysis of the NATO Standardization Definitions, Structure, Process and Products is provided in the related sub-section.


European Union (EU)[3]

A complementary activity to NATO on defense standardization is undertaken by the European Union. A brief analysis of the EU defense standardization activities is presented in the related subsection.

As far as the European Defense Procurement Framework is concerned the European Commission Directive 2009/81/EC defines the following definitions related to defense standardization.

Technical specification

(in the case of works contracts)

The totality of the technical prescriptions contained in particular in the tender documents, defining the characteristics required of a material, product or supply, which permits a material, a product or a supply to be described in a manner such that it fulfils the use for which it is intended by the contracting authority/entity. These characteristics shall include levels of environmental performance, design for all requirements (including accessibility for people with disabilities) and conformity assessment, performance, safety or dimensions, including the procedures concerning quality assurance, terminology, symbols, testing and test methods, packaging, marking and labelling and production processes and methods. They shall also include rules relating to design and costing, the test, inspection and acceptance conditions for works and techniques or methods of construction and all other technical conditions which the contracting authority/entity is in a position to prescribe, under general or specific regulations, in relation to the finished works and to the materials or parts which they involve;

Technical specification

(in the case of supply or service contracts)

A specification in a document defining the required characteristics of a product or service, such as quality and environmental performance levels, design for all requirements (including accessibility for people with disabilities), and conformity-assessment, performance, use of the product, its safety or dimensions, including requirements relevant to the product as regards the name under which the product is sold, terminology, symbols, testing and test methods, packaging, marking and labelling, user instructions, production methods and procedures, as well as conformity assessment procedures;


A technical specification approved by a recognized standardization body for repeated or continuous application, compliance with which is not compulsory, from one of the following categories:

  • International standard: a standard adopted by an international standards organization and made available to the general public,
  • European standard: a standard adopted by a European standardization body and made available to the general public,
  • National standard: a standard adopted by a national standards organization and made available to the general public,

Defense Standard

A technical specification the observance of which is not compulsory and which is approved by a standardization body specializing in the production of technical specifications for repeated or continuous application in the field of defense.

Military equipment

Equipment specifically designed or adapted for military purposes and intended for use as an arm, munitions or war material.

Life cycle

All the possible successive stages of a product, i. e. research and development, industrial development, production, repair, modernization, modification, maintenance, logistics, training, testing, withdrawal and disposal.

Research and development

All activities comprising fundamental research, applied research and experimental development, where the latter may include the realization of technological demonstrators, i.e., devices that demonstrate the performance of a new concept or a new technology in a relevant or representative environment.


U.S Defense Standards[4]

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.

Defense standards are also used by other non-defense government organizations, technical organizations, and industry.

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 U.S 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, Defense Standardization Program (DSP) Procedures, November 2014, USD (Acquisition, Technology and Logistics):



Definition [1]


Defense Handbook

A document that provides standard procedural, technical, engineering, or design information about the materiel, processes, practices, and methods covered by the DSP. MIL-STD-967 covers the content and format for defense handbooks.


Defense Specification

A document that describes the essential technical requirements for military-unique materiel or substantially modified commercial items. MIL-STD-961 covers the content and format for defense specifications.


Defense Standard

A document that establishes uniform engineering and technical requirements for military-unique or substantially modified commercial processes, procedures, practices, and methods. There are five types of defense standards: interface standards, design criteria standards, manufacturing process standards, standard practices, and test method standards. MIL-STD-962 covers the content and format for defense standards.


Performance Specification

A performance specification states requirements in terms of the required results with criteria for verifying compliance but without stating the methods for achieving the required results. A performance specification defines the functional requirements for the item, the environment in which it must operate, and interface and interchangeability characteristics.


Detail Specification

A specification that states design requirements, such as materials to be used, how a requirement is to be achieved, or how an item is to be fabricated or constructed. A specification that contains both performance and detail requirements is still considered a detail specification.



Referencing Civil Standards in Defense Standards

As already mentioned in the civil standards section, practical referencing of civil standards in a consistent manner and in the appropriate section within a Defense Standard is a valuable tool that eliminates the repetition of requirements and tests adequately set forth elsewhere. It also helps to minimize the costs of compliance, reduces excessive citation of documents, eliminates ambiguities, and helps to identify which civil standard is required for the implementation of a Defense Standard.

All references, in-text citations, quotations or paraphrasing of civil standards must correspond to an entry in the Normative or Informative References section within the Defense Standard. Listing a reference in its appropriate section eliminates ambiguity and helps to identify which civil standards are required for the implementation of the Defense Standard.

Normative Reference. Normative references are those directly cited in the document as part of the requirement. When listing a civil standard in this section, it is advisable to use the following convention: the civil SDO, the document’s identification number and title, and source for obtaining copies. Where only a portion of a civil standard is needed, the Defense Standard Publisher should specify only the applicable requirements by paragraph or section title or subject matter (it is advisable not to use paragraph numbers or page numbers as these may change when documents are revised), or directly copy the pertinent portion into the Defense Standard after permission of the copyright holder is obtained.

Informative Reference. Informative references are those listed for information purposes only and are not part of any requirement (supplementary information). When listing a civil standard in this section, it is advisable to use the following convention: the civil SDO, and the document’s identification number and title.


Analysis on the implementation of defense standards is provided in the section Best Practices.

[1] The ability of one product, process or service to be used in place of another to fulfil the same requirements[Source: ISO/IEC Guide 2:2004]

[2] Source: Allied Administrative Publication AAP-03 (K) V1 “Directive for the Production, Maintenance and Management of NATO Standardization Documents”

[3] The terms and definitions presented in the section European Union are defined in Annex III of the 2009/81/EC Directive

[4] The source used for the information provided in the section U.S Defense Standards is Wikipedia


Source note:

Sources for the Information provided in this section are the EU Portal, Wikipedia and the NATO Standardization Office public website