This case study details the options evaluated and path chosen by a United States (US) Department of Defense (DoD) software development organization to re‐engineer four existing products with common features into a single product‐line resulting in product sponsors taking advantage of cost savings, developers shortening implementation and testing timeframes, and users obtaining product features faster while sharing a common experience across product variants. Although the software‐intensive products were originally a product line operating from a common code repository, they diverged due to different product sponsors having differing priorities and schedule commitments. The mission scope of each variant differs leading to a commonality range of approximately 20% to 70% based on the quantity of common features. The re‐engineering options evaluated included merging common code and maintaining it in a single repository; re‐using software code while keeping it in separate repositories for each product variant; and pursuing a Modular Open Systems Approach (MOSA) to create common modules for insertion, updating, and replacement within any product variant without disrupting the rest of that product. With product sponsor support, the DoD project decided to pursue a hybrid approach of immediate code re‐use complemented with an agile approach to MOSA implementation. This solution allowed the project to re‐engineer the four existing product variants while still meeting sponsor, DoD, and end‐user operational needs.