User-in-the-Loop or User-Out-of-the-Loop: Acquisition Strategies as Indicators of Human Factors Practices in Software-Centric Defense Programs

Abstract

Human factors (HF), including human-centered design, user experience, and human systems integration, play a crucial role in the operational effectiveness of defense software and digital systems. HF practices involve user focused activities such as user interviews, product design, usability testing, training, safety assessments, and early prototyping. Some Army acquisition programs have applied “soldier-centered design” to address HF in defense systems, but these approaches are inconsistently embedded due to limited early involvement of HF specialists and the frequent omission of HF requirements in DoD contract solicitations. This lack of emphasis in contracts leads contractors to deprioritize HF to remain competitive on price, limiting the routine integration of HF practices in defense systems. This study aims to investigate how acquisition strategies influence the prioritization of HF in software-centric programs, recognizing that certain contract and acquisition methods may better support HF practices such as user touchpoints and soldier-centered design. Additionally, it explores whether acquisition methods commonly used by traditional primes versus “defense tech” vendors correspond to differing levels of HF integration. A mixed sample of major software-centric defense programs, spanning traditional primes and commercial dual-use/“defense tech” vendors, is analyzed by constructing an HF score based on proxy criteria derived from contract characteristics, acquisition pathways, and indicators of iterative development or user interaction. External sources, including DOT&E reports, GAO assessments, and program press releases, are then used to validate whether programs with higher proxy HF scores experience fewer human-factors deficiencies, better usability outcomes, or reduced rework. By establishing a data-driven method to infer HF activity from acquisition data, this study provides a replicable analytical framework for evaluating user-centered development across defense programs, supporting a systematic understanding of where and how warfighter-centered design is occurring within DoD acquisition.