How Defence Works: the defence operating model (superseded by Defence Reform)
This document is no longer current. It provides a description of the organisational structure of Defence and how its organisations worked together before the departmental reforms that came into effect on 31 March 2025.
Documents
Details
This document describes the way Defence worked prior to the departmental reforms that came into effect on 31 March 2025, and is no longer an accurate description of how Defence works. In due course an updated document will published that builds on the information below and outlines how each part of the department works following these reforms.
Under the Secretary of State and Ministers, UK Defence will now be led by a strengthened Department of State, a fully-fledged Military Strategic Headquarters, a new National Armaments Director Group, and the Defence Nuclear Enterprise. Our new leadership “Quad” - the Permanent Secretary, Chief of the Defence Staff, National Armaments Director, and Chief of Defence Nuclear - will ensure that their teams work together across these structures to deliver our key defence departmental outcomes in collaboration. Defence Reform is designed to introduce new integrated ways of working together and making individuals more accountable – the driving principles of the government’s Defence Reform agenda.
How Defence Works explains how defence is structured and governed, how key decisions are taken, and how 7 core activities (policy, strategy, planning, governance, generate, enable, and operate) are carried out by 18 organisations and 16 key business functions, working together to deliver 3 defence outputs (defence policy, military capability, and military operations).
This publication replaces the December 2015 edition of How Defence Works.
Updates to this page
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Webpage updated with information about the Defence Reform programme.
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Added the new version of the How Defence works and updated the details on the page.
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Addition of information stating that a fully revised version of ‘How Defence Works’ is in development and will be available from Spring 2020.
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Updated to version 4.2.
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First published.