What it is
STANAG 4157 is a NATO Standardization Agreement, currently Edition 3, promulgated on 27 February 2017 and superseding Edition 2. Like every STANAG, it is not itself a technical specification. It is the agreement by which NATO member nations commit to implement one, and the specification lives in the Allied Publications it covers: here, AOP-4157 Edition A and AOP-20 Edition B, which carry the standardized test requirements for the safety and suitability for service assessment of Safety, Arming and Functioning Systems (SAF Systems) used in munitions.
What the agreement responds to
The document states its own aim plainly: it responds to an interoperability requirement, to facilitate joint and multinational use and exchange of munitions by prescribing standardized test requirements for the safety and suitability for service assessment of SAF Systems. It goes on to say that using those standardized tests contributes to user safety during the storage, transportation and deployment of munitions. That is the whole technical commitment this cover makes. The testing itself, and what it looks for, is the subject of AOP-4157 and AOP-20, not of this document.
Ratification and what counts as implemented
A STANAG binds a nation, not a company, and only once that nation ratifies it, with the ratification reflected in the NATO Standardization Document Database (NSDD). This edition is effective on receipt and is to be used by the nations and NATO bodies that have ratified it; partner nations are separately invited to adopt it. The document is specific about what "implemented" means: a nation has implemented STANAG 4157 when its safety and suitability for service testing is carried out in compliance with this STANAG, AOP-4157 (A) and AOP-20 (B), and when the nation has the required national procedures in place. Nations report their ratification and implementation intentions to the NATO Standardization Office, and their actual implementation details, using the forms in Annex H (nations) and Annex G (partner nations) to AAP-03. None of that reporting reaches a supplier directly. It reaches a supplier when a national procurement authority puts SAF Systems testing to this STANAG into a tender or a contract, which is the point at which the STANAG stops being an agreement between nations and starts being something a programme has to meet.
Review and currency
The STANAG is reviewed at least once every three years, with the outcome recorded in the NSDD. A nation or NATO body can propose a change at any point through a standardization proposal to the tasking authority, and it is processed at the next review. This edition, 3, superseded Edition 2.
No certification attaches to this agreement
This cover names no certification scheme and no accredited or notified body, because there is nothing here for an organisation to be certified against. What it describes is a nation's implementation, judged by whether its testing and national procedures meet the STANAG, AOP-4157 and AOP-20, not a certificate a company can hold.
The publications it covers, and what else it points to
The two publications a participating nation actually commits to are AOP-4157 (Edition A) and AOP-20 (Edition B). Everything else the cover lists is related reading rather than a further obligation: STANAG 4187 on fuzing systems safety design, STANAG 4170 on qualifying explosive materials for military use, STANAG 4297 on assessing the safety and suitability for service of non-nuclear munitions, STANAG 4363 on development testing of lead and booster explosive components, STANAG 4439 on insensitive munitions, STANAG 4497 on hand emplaced munitions design, STANAG 4370 on environmental testing, STANAG 4560 on electro-explosive device characterization, STANAG 4238 on electrical and electromagnetic environments, STANAG 4326 on fuze characteristics data, and AAP-03, whose annexes carry the reporting forms above. Two further items in the same list, AOP-42 and AOP-38, are outside our catalogue.