This paper provides an overview of Calibre Off-The-Shelf Software (OTSS) validation required by the Food and Drug Administration (FDA) for implantable medical devices. It is based on a Mentor Graphics (MGC) generated Calibre Quality Assurance (QA) document combined with internal Calibre® DRC/LVS in-house testing performed at Boston Scientific (BSC). The following Calibre QA issues will be emphasized first: product lifecycle models, release risk management and monitoring, defect classification, tracking and reporting, functional validation and regression testing, quality metrics. Following the Calibre QA introduction, it will cover these specific topics: project setup, performing Calibre DRC, LVS and XOR tests, regression suite and final results verification scripting, and correlation of vendor assessment of quality versus internal testing outcomes to complete OTSS Calibre validation.