Least Burdensome

Least Burdensome is the FDA principle of the least required effort: generate no more effort and evidence than controlling the identified risk demands. It explicitly does not mean testing or documenting as little as possible – high risk still requires high rigor. In practice it means, for example: using existing supplier evidence, digital system records instead of redundant screenshots, unscripted or exploratory testing where it fits better, and focusing your own tests on genuine evidence gaps. The FDA has carried the principle for a long time (“General Principles of Software Validation”, 2002, as a stated principle); the final CSA guidance (2025) makes it the core of the risk-based assurance approach: “the burden of validation is no more than necessary to address the risk”.