CSA
Computer Software Assurance (CSA)
Computer Software Assurance is a risk-based approach to establishing confidence in software used in production and the quality system. It emphasizes critical thinking and appropriate testing over documentation volume.
What CSA actually changes
CSA does not remove the obligation to establish that software is fit for its intended use. It challenges the assumption that every function deserves identical scripted testing and identical documentation weight.
The shift is analytical: identify the intended use, determine whether a failure could compromise product quality or patient safety, then choose assurance activities proportionate to that determination. Low-risk features may be appropriately assured through unscripted or exploratory testing with lightweight records; high-risk features still warrant rigorous, scripted, pre-approved testing.
CSA is not a replacement for CSV
It is inaccurate to say CSA simply replaces CSV. Both are approaches to the same underlying objective: confidence that a computerized system performs as intended in its context of use. Many organizations operate a single assurance framework that scales its rigor by risk, and describe it using whichever terminology fits their quality system.
What matters to a regulator or auditor is whether the approach is justified, applied consistently, and supported by evidence — not the label on the SOP.
Assurance activities by risk
- Unscripted testing — ad hoc, error-guessing and exploratory testing, recorded proportionate to risk
- Scripted testing — robust or limited scripted tests with predefined steps and expected results
- Supplier leverage — assessed vendor testing, certifications and release evidence
- Production monitoring — post-release checks, error logs and performance signals
Making CSA work in a real quality system
- Update the validation policy and SOPs so the risk framework is authorized, not improvised
- Train reviewers and approvers, not just authors — approval culture is what re-creates paperwork
- Define what evidence unscripted testing must capture (who, when, what, result, defects)
- Keep traceability for high-risk requirements
- Do not use CSA as a justification to skip Part 11 or data integrity assessment
Primary references
- FDA — Computer Software Assurance for Production and Quality System Software
- FDA — General Principles of Software Validation
Information published on ValidationEngineering.com is educational and informational. It is not legal or regulatory advice and is not a guarantee of regulatory compliance or of any inspection outcome. Organizations remain responsible for their own quality decisions.
FAQ
CSA — common questions
- How does CSA differ from traditional CSV?
- CSA reallocates effort from documentation to critical thinking and testing. Higher-risk features get scripted testing; lower-risk features can be covered by unscripted or ad-hoc testing with lighter evidence. The regulatory obligation to demonstrate fitness for intended use is unchanged.
- Is unscripted testing acceptable to FDA?
- Yes, for appropriate risk levels. FDA's Computer Software Assurance guidance explicitly recognizes unscripted testing, including exploratory and error-guessing approaches, when the risk determination supports it and the record captures who tested what and the outcome.
- What evidence does CSA still require?
- Intended use, risk determination, the testing performed, issues found and resolved, and a conclusion. Screenshots of every step are not required; a defensible record of the thinking and the result is.
Next step
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