The Sentinel Papers — SPK-01 — Counting the Breach: A Unit-Cost Computability Kernel for Nunn-McCurdy Oversight

The Nunn-McCurdy Act (10 U.S.C. §§ 4371–4376) has served as the primary statutory mechanism for Congressional oversight of Major Defense Acquisition Program cost growth since 1982. Despite four decades of implementation, three structural gaps compromise the Act's effectiveness: unit definition ambiguity for complex system-of-systems programs, baseline comparability failures caused by unstructured programmatic adjustments, and computational non-reproducibility of breach determinations.

These gaps have material consequences. The Government Accountability Office documented that programmatic adjustments masked approximately 50% of breaches between 2001 and 2003 (GAO-05-182). The LGM-35A Sentinel ICBM program's 2024 critical breach — 81% Program Acquisition Unit Cost growth from $118M to $214M per unit, driven primarily by underestimated civil infrastructure — demonstrated that even modern programs lack analytical infrastructure for transparent cost accountability.

This paper proposes the Unit-Cost and Breach Computability Kernel (UC-BCK), an architectural layer integrated with existing Department of Defense data systems — the Defense Acquisition Visibility Environment (DAVE) and the Cost Assessment Data Enterprise (CADE) — that transforms Nunn-McCurdy compliance from a document-based narrative process into a computationally reproducible, auditable analytical capability. UC-BCK does not modify statutory definitions or automate certification decisions. It operationalizes existing law by establishing machine-enforceable unit definitions, creating traceable baseline-to-current cost element mappings, computing statutory metrics from FlexFile source data, producing multiple simultaneous analytical views (statutory, raw, quantity-neutral, segment-decomposed, contested), and generating evidence ledgers enabling independent replay verification.

The proposed architecture requires no statutory changes, leverages existing data collection authorities under 10 U.S.C. § 3227, and can be implemented within current Defense Business System infrastructure. All 44 source citations have been independently verified through blind fact-checking against primary sources.

This paper is SPK-01 within the Sentinel Recovery Architecture, a seven-spoke constraint satisfaction analysis of the Sentinel ICBM program. The post-restructure baseline (February 2026) is incorporated throughout.