§4402 — Title 10 Armed Forces | U.S. Code

§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 V— ACQUISITION › Subpart F— Major Systems, Major Defense Acquisition Programs, and Weapon Systems Development › Chapter 327— WEAPON SYSTEMS DEVELOPMENT AND RELATED MATTERS › Subchapter I— MODULAR OPEN SYSTEM APPROACH IN DEVELOPMENT OF WEAPON SYSTEMS › § 4402

Last updated Apr 18, 2026|Official source

Summary

Require program planning papers for big weapon buys to say how system needs might change over time and what the minimum capability must be for the system to start operating. The Director of Cost Assessment and Performance Evaluation must make sure studies of alternatives look at evolutionary buying, prototypes, and using a modular open system approach (MOSA). If a program uses MOSA, its acquisition plan must explain the MOSA, separate the main platform from the parts, say which parts may be added, removed, or swapped later, name other parts that might be added in the future, explain how rights to designs and technical data will be handled, and explain how integration and configuration control will protect the mission and information. The milestone decision authority must make sure requests for proposals describe the MOSA and the minimum parts that must be in the design. Milestone B approval cannot happen until the authority writes that either the program has set interfaces between platform and parts that meet requirements and the Government has arranged needed rights to those interfaces, or that MOSA is not practical. The military department Secretaries must issue guidance to put these rules into practice.

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.

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.

§4402 Requirement to Address Modular Open System Approach in Program Capabilities Development and Acquisition Weapon System Design

Summary

Title 10, §4402

Notes & Related Subsidiaries

Editorial Notes

Amendments

Statutory Notes and Related Subsidiaries

Effective Date

Effective Date

Citations & Metadata