Submarine construction oversight requires coordinated documentation, accountable decisions, and timely communication, yet fragmented information systems often complicate quality assurance and governance in complex naval programs. To address this, the study formulates functional and nonfunctional requirements to propose an integrated decision support information system architecture for technical consultants supporting Indonesian Navy submarine construction oversight. Using a qualitative, design-oriented approach combining stakeholder interviews, document analysis, workflow mapping, and requirements prioritization, the architectural modeling examines user roles, information flows, access controls, interoperability, and auditability based on systems engineering principles. The resulting design is a modular platform integrating document management, requirements traceability, inspection reporting, issue tracking, and decision records within a secure governance framework, evaluated on usability, traceability, consistency, accountability, and security compliance. The study concludes that this human-centered architecture can enhance coordination and transparency without replacing professional engineering judgment, while recommending future research to validate requirements, test prototypes, and quantify administrative and decision-making improvements while safeguarding sensitive technical data