Choosing between custom software and off‑the‑shelf (COTS) can define your roadmap for years. This guide breaks down costs, timelines, risks, and outcomes—then gives you a simple decision framework. 1) Total Cost of Ownership (TCO) 2) Time-to-Value 3) Scalability & Fit 4) Security & Compliance 5) Risk & Vendor Lock‑in Decision Checklist