A Document Management System (DMS) is the most appropriate choice as it is specifically designed for the lifecycle management of controlled documents, such as Standard Operating Procedures (SOPs). A DMS provides essential, built-in functionalities for version control, access restrictions, secure electronic signatures, automated workflows for review and approval, and a complete audit trail. These features are critical for maintaining data integrity and ensuring compliance with regulatory standards (e.g., GxP, 21 CFR Part 11) common in the clinical data management field. It ensures that personnel always access the current, effective version of an SOP, which is a fundamental requirement of a quality management system.

A customized Excel spreadsheet lacks the robust security, version control, workflow automation, and audit trail capabilities required for managing regulated documents and is highly prone to human error. A Learning Management System (LMS) is designed to administer and track training on SOPs, not to control the authoring, review, approval, and versioning of the SOP documents themselves. An existing paper filing system is inefficient, lacks automated controls, is difficult to secure and distribute, and makes retrieving historical versions or proving compliance via audit trails extremely cumbersome.

1. Society for Clinical Data Management. (2023). Good Clinical Data Management Practices (GCDMP). Section 3.1, "Standard Operating Procedures," states that critical processes must be documented in SOPs or other "controlled documents." A DMS is the standard industry tool for establishing and maintaining such control over electronic documents.

2. Gogtay, N. J., & Thatte, U. M. (2017). Standard operating procedures. Journal of the Association of Physicians of India, 65(5), 69-72. This article details the SOP lifecycle (creation, review, approval, distribution, archival), which outlines processes that are most effectively and compliantly managed by a dedicated Document Management System.

3. Krishnankutty, B., Bellary, S., & Kumar, N. B. R. (2012). Data management in clinical research: An overview. Indian Journal of Pharmacology, 44(2), 168–172. https://doi.org/10.4103/0253-7613.93842. The paper emphasizes the necessity of SOPs for ensuring quality and consistency in clinical research (p. 170). The management of these critical documents necessitates a formal system with features like versioning and access control, which are hallmarks of a DMS.