Title 10Armed ForcesRelease 119-73

§4402 Requirement to address modular open system approach in program capabilities development and acquisition weapon system design

Title 10 › Subtitle Subtitle A— - General Military Law › Part PART V— - ACQUISITION › Subpart Subpart F— - Major Systems, Major Defense Acquisition Programs, and Weapon Systems Development › Chapter CHAPTER 327— - WEAPON SYSTEMS DEVELOPMENT AND RELATED MATTERS › Subchapter SUBCHAPTER I— - MODULAR OPEN SYSTEM APPROACH IN DEVELOPMENT OF WEAPON SYSTEMS › § 4402

Last updated Apr 6, 2026|Official source

Summary

Require program plans for major defense acquisition programs to say how system needs might change over the life of the system and what the minimum acceptable capability must be for initial operation. Require the Director of Cost Assessment and Performance Evaluation to make sure studies of alternatives look at evolutionary development, prototyping, and a modular open system approach. If a program uses a modular open system approach, its acquisition plan must explain that approach, separate the main platform from the components, say which components may be added, replaced, or removed later, and explain how intellectual property and technical data will be handled and how systems integration and configuration control will work. Requests for proposals must describe the approach and the minimum components to include. Milestone B cannot be approved until the decision authority finds, in writing, that interfaces are defined, necessary rights to those interfaces will be obtained, or that a modular approach is not practical. The military department Secretaries must issue guidance to put these rules into practice.

Full Legal Text

Title 10, §4402

Armed Forces — Source: USLM XML via OLRC

(a)A program capability document for a major defense acquisition program shall identify and characterize—
(1)the extent to which requirements for system performance are likely to evolve during the life cycle of the system because of evolving technology, threat, or interoperability needs; and
(2)for requirements that are expected to evolve, the minimum acceptable capability that is necessary for initial operating capability of the major defense acquisition program.
(b)The Director of Cost Assessment and Performance Evaluation, in formulating study guidance for analyses of alternatives for major defense acquisition programs and performing such analyses under section 139a(d)(4) of this title, shall ensure that any such analysis for a major defense acquisition program includes consideration of evolutionary acquisition, prototyping, and a modular open system approach.
(c)In the case of a major defense acquisition program that uses a modular open system approach, the acquisition strategy required under section 4211 of this title shall—
(1)clearly describe the modular open system approach to be used for the program;
(2)differentiate between the major system platform and major system components being developed under the program, as well as major system components developed outside the program that will be integrated into the major defense acquisition program;
(3)clearly describe the evolution of major system components that are anticipated to be added, removed, or replaced in subsequent increments;
(4)identify additional major system components that may be added later in the life cycle of the major system platform;
(5)clearly describe how intellectual property and related issues, such as technical data deliverables, that are necessary to support a modular open system approach, will be addressed; and
(6)clearly describe the approach to systems integration and systems-level configuration management to ensure mission and information assurance.
(d)The milestone decision authority for a major defense acquisition program that uses a modular open system approach shall ensure that a request for proposals for the development or production phases of the program shall describe the modular open system approach and the minimum set of major system components that must be included in the design of the major defense acquisition program.
(e)A major defense acquisition program may not receive Milestone B approval under section 4252 of this title until the milestone decision authority determines in writing—
(1)in the case of a program that uses a modular open system approach, that—
(A)the program incorporates clearly defined major system interfaces between the major system platform and major system components, between major system components, and between major system platforms;
(B)such major system interfaces are consistent with the the 11 So in original. requirements of section 4401(a) of this title; and
(C)the Government has arranged to obtain appropriate and necessary intellectual property rights with respect to such major system interfaces upon completion of the development of the major system platform; or
(2)in the case of a program that does not use a modular open system approach, that the use of a modular open system approach is not practicable.
(f)The Secretaries of the military departments shall issue guidance to implement the requirements of this section.

Legislative History

Notes & Related Subsidiaries

Editorial Notes

Amendments

2025—Subsec. (e)(1)(B). Pub. L. 119–60 substituted “the requirements of section 4401(a) of this title” for “widely supported and consensus-based standards that exist at the time of the milestone decision, unless such standards are unavailable or unsuitable for particular major system interfaces”. 2021—Pub. L. 116–283, § 1851(b)(1), renumbered section 2446b of this title as this section. Subsec. (c). Pub. L. 116–283, § 1851(b)(3)(A), substituted “section 4211” for “section 2431a” in introductory provisions. Subsec. (e). Pub. L. 116–283, § 1851(b)(3)(B), substituted “section 4252” for “section 2366b” in introductory provisions. 2019—Subsec. (f). Pub. L. 116–92 added subsec. (f). 2017—Subsec. (e). Pub. L. 115–91 substituted “in writing—” for “in writing that—” in introductory provisions and inserted “, that” after “open system approach” in introductory provisions of par. (1).

Statutory Notes and Related Subsidiaries

Effective Date

of 2021 AmendmentAmendment by Pub. L. 116–283 effective Jan. 1, 2022, with additional provisions for delayed implementation and applicability of existing law, see section 1801(d) of Pub. L. 116–283, set out as a note preceding section 3001 of this title.

Effective Date

Section effective Jan. 1, 2017, see section 805(a)(4) of Pub. L. 114–328, set out as a note under section 4401 of this title.

Reference

Citations & Metadata

Citation

10 U.S.C. § 4402

Title 10Armed Forces

Last Updated

Apr 6, 2026

Release point: 119-73