FAR 11.101—Order of precedence for requirements documents.
Plain-English Summary
FAR 11.101 tells agencies how to choose, build, and prioritize the documents that define what they are buying. It covers the order of precedence among requirements documents, including documents mandated by law, performance-oriented documents such as performance work statements (PWSs) and statements of objectives (SOOs), detailed design-oriented documents, and certain Government-issued standards, specifications, and related publications used for non-repetitive acquisitions. It also addresses the separate requirement to use voluntary consensus standards under OMB Circular A-119 and the National Technology Transfer and Advancement Act, unless doing so would be inconsistent with law or impractical. In practice, this section pushes agencies toward clearer, more outcome-based requirements and away from unnecessary Government-unique specifications. For contractors, it affects how requirements are interpreted, how proposals are structured, and what technical approach will be judged acceptable. For contracting officers and acquisition teams, it is a key policy for drafting requirements documents, avoiding over-specification, and ensuring compliance with federal standards policy.
Key Rules
Follow the precedence order
Agencies may select, modify, combine, or create requirements documents, but they must do so in the order of precedence stated in the rule. Documents mandated by law come first, followed by performance-oriented documents, then detailed design-oriented documents, and finally certain Government-issued standards and specifications for non-repetitive acquisitions.
Use law-mandated documents first
If a statute or other legal requirement mandates a particular requirements document or content, that requirement controls. Agencies cannot replace or override a legal mandate by choosing a different document type.
Prefer performance-based requirements
Performance-oriented documents such as a PWS or SOO are preferred over detailed design specifications when they can meet the agency’s needs. This means the agency should describe the desired outcome or performance level rather than prescribing exactly how the contractor must do the work, unless a more detailed approach is justified.
Use design documents when needed
Detailed design-oriented documents are lower in the order of precedence, but they remain available when performance-based descriptions are not sufficient to define the requirement. Agencies may use them when the acquisition needs precise technical direction, compatibility, safety, or other mission-driven detail.
Limit Government-unique standards
Government standards, specifications, and related publications outside the Defense or Federal series may be used for non-repetitive acquisitions, but they are not the preferred default. Agencies should not rely on Government-unique requirements when a performance-based or consensus-based alternative will satisfy the need.
Use voluntary consensus standards
Under OMB Circular A-119 and the NTTAA, agencies must use voluntary consensus standards when they exist instead of Government-unique standards, unless that would be inconsistent with law or otherwise impractical. Examples include industry standards such as ISO 9000 and IEEE 1680, which are developed and administered by the private sector.
Document exceptions carefully
If an agency does not use an available voluntary consensus standard, it should be able to explain why the standard is inconsistent with law or impractical to use. This creates a record that supports the acquisition approach and helps defend the requirements strategy.
Responsibilities
Agency
Choose, modify, combine, or create requirements documents in accordance with the order of precedence. Use voluntary consensus standards when available, and avoid unnecessary Government-unique standards or overly detailed specifications unless justified by the acquisition need.
Contracting Officer
Ensure the solicitation and contract requirements reflect the proper document hierarchy and comply with FAR policy, OMB Circular A-119, and the NTTAA. Verify that any departure from voluntary consensus standards or performance-based requirements is supportable and documented.
Program/Requirements Personnel
Define the agency need in the most effective document type, preferably performance-oriented when feasible. Identify applicable legal mandates, available consensus standards, and any technical or mission reasons that require more detailed design specifications.
Contractor
Review the requirements documents in the order presented and base the proposal and performance approach on the controlling requirements. Raise questions when requirements appear inconsistent, overly prescriptive, or in conflict with higher-precedence documents or applicable consensus standards.
Standards-Setting or Technical Community
Develop, maintain, and apply voluntary consensus standards where appropriate, and support agency use of those standards in place of Government-unique standards when feasible.
Practical Implications
This section encourages agencies to write requirements around outcomes, which can give contractors more flexibility and innovation room. Contractors should pay close attention to whether the solicitation is performance-based or design-based, because that affects how much discretion they have in meeting the requirement.
A common pitfall is over-specifying the work with detailed design requirements when a PWS or SOO would be enough. That can limit competition, increase cost, and create unnecessary compliance burdens.
Another frequent issue is failing to check for voluntary consensus standards before using a Government-unique specification. Agencies should be prepared to justify why a consensus standard was not used, and contractors should watch for opportunities to propose compliant alternatives.
When multiple requirements documents exist, the order of precedence matters if there is a conflict. Both contracting officers and contractors should identify which document controls and resolve inconsistencies early, before award or during performance.
For non-repetitive acquisitions, Government-issued standards and specifications may still be used, but they should not be the default choice. The practical takeaway is to use the least prescriptive document that still clearly defines the need and supports mission success.
Official Regulatory Text
(a) Agencies may select from existing requirements documents, modify or combine existing requirements documents, or create new requirements documents to meet agency needs, consistent with the following order of precedence: (1) Documents mandated for use by law. (2) Performance-oriented documents ( e.g., a PWS or SOO). (See 2.101 .) (3) Detailed design-oriented documents. (4) Standards, specifications and related publications issued by the Government outside the Defense or Federal series for the non-repetitive acquisition of items. (b) In accordance with OMB Circular A-119, "Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities," and Section 12(d) of the National Technology Transfer and Advancement Act of 1995, Pub. L. 104-113 ( 15 U.S.C. 272 note), agencies must use voluntary consensus standards, when they exist, in lieu of Government-unique standards, except where inconsistent with law or otherwise impractical. The private sector manages and administers voluntary consensus standards. Such standards are not mandated by law ( e.g. , industry standards such as ISO 9000, and IEEE 1680).