What’s Changed in CSA Implementation Since 2024: A Practical 2026 Update

The CSA Starting Point in 2024

The September 13, 2022 publication of the FDA’s draft guidance, Computer Software Assurance for Production and Quality System Software, available through the FDA guidance landing page, marked an explicit regulator-led pivot away from documentation-heavy validation practice toward a risk-based assurance posture. The guidance was directed primarily at medical device manufacturers under 21 CFR Part 820 but had immediate implications for pharma quality teams operating under analogous CSV expectations.

The 2022 draft articulated several principles that 2024 implementation work had to translate into operational practice:

• Risk-based testing scope, with testing depth calibrated to the intended use of the software and the consequences of failure
• Use of “unscripted testing” approaches (exploratory, ad-hoc, error-guessing) alongside scripted testing where appropriate
• Leveraging vendor activities and documentation rather than recreating evidence the vendor has already produced
• Documentation focused on demonstrating assurance, not on documentation volume for its own sake
• The “least burdensome approach” applied to validation activities

By 2024, quality teams across pharma and device industries had begun translating these principles into practice, but the translations varied considerably. Some teams adopted CSA quickly and aggressively; others remained cautious, particularly in regulated GxP environments where the volume of historical CSV documentation served as inspection-readiness comfort.

As Kneat’s October 2024 analysis of the CSA guidance status noted, by the second anniversary of the draft, industry practice had matured enough to reveal which CSA implementation patterns held up under inspection and which did not. The patterns that worked were converging.

What Has Changed in Practice Since 2024

The most significant shift in CSA implementation since 2024 is not at the principle level but at the operational practice level. Several recognizable changes:

Risk-based testing scope has matured into defensible practice. Quality teams that initially struggled to articulate testing scope by risk now have established SOPs that survive inspection. The shift is from “we tested everything” to “we tested the use cases proportional to their risk, and here is the documented rationale.” Inspectors increasingly accept this framing when it is supported by clear documentation.

Vendor leverage has become more sophisticated. The 2024 patterns of vendor leverage were often nominal — accepting vendor documentation without independent assessment. The 2026 patterns are more rigorous: independent assessment of vendor practices, documented vendor qualification, and selective reliance on vendor evidence calibrated to the criticality of the use. The improvement reflects two years of industry learning about what survives inspection scrutiny.

Documentation has become more targeted. Quality teams that initially produced CSA documentation that looked structurally similar to traditional CSV documentation (just with risk-based scope) have moved to documentation that genuinely reflects the assurance posture. Risk assessment documentation is more substantive, testing documentation is more focused, and overall documentation volume is materially lower for low-risk uses while remaining substantial for high-risk uses.

Cross-functional governance has strengthened. CSA implementation requires QA, IT, the use case owner, and the vendor management function to align on risk assessment, vendor qualification, and testing scope decisions. Quality teams that operate CSA through a cross-functional governance structure consistently produce better documentation and faster validation cycles than teams operating it through QA alone.

AI and SaMD integration has emerged as a question. The 2022 draft guidance was focused on production and quality system software, not on AI/ML-enabled systems. As AI use has matured in pharma and device manufacturing, the question of how CSA principles interact with AI-specific validation requirements has emerged as a substantive integration challenge. We address this directly in a later section.

The Risk-Based Testing Patterns That Work

The risk-based testing patterns that have held up under inspection share recognizable structural features. The pattern that has worked across our client engagements:

The tier classification itself is the most important upstream discipline. Quality teams that produce defensible risk tier classifications find that downstream testing scope decisions are well-supported; teams that produce ambiguous classifications find that downstream decisions require continuous re-litigation.

An important refinement that emerged in 2024-2026 practice: the risk tier of the use case can differ from the risk tier of the software. A general-purpose software product used in a high-risk use case carries the use case’s risk tier for that deployment; the same software product used in a low-risk use case can be validated to the lower tier. This use case-specific tiering is more nuanced than the product-level tiering that traditional CSV practice often defaulted to, and it materially reduces validation burden for software used across multiple use cases of differing risk.

As ISPE’s analysis of critical thinking in quality risk management evolution notes, the discipline of risk-based scope requires meaningful critical thinking effort from the validation team — and the practical reduction in validation burden depends on that thinking effort being applied rigorously. Teams that defer the critical thinking and apply default tiers do not capture the CSA benefit.

Leveraging Vendor Documentation Properly

Vendor leverage is one of the CSA areas where 2024-2026 practice has matured most significantly. The principles articulated in the 2022 draft are well-established; the practice of applying them defensibly has been the work of the past two years.

The patterns that hold up under inspection share several features:

Documented vendor qualification. Before relying on vendor documentation for validation, the vendor’s practices are independently assessed and documented. The qualification is risk-based: more rigorous for vendors supporting high-risk use cases, lighter for vendors supporting low-risk uses.

Selective rather than wholesale reliance. Quality teams that rely on the vendor for everything produce documentation that inspectors scrutinize for completeness. Quality teams that articulate specifically which vendor evidence is being relied upon, and which validation activities are being performed independently, produce documentation that survives scrutiny.

Documented assessment of vendor evidence. Vendor evidence is not accepted on faith. The quality team’s independent assessment of the vendor’s testing methodology, the relevance of the vendor’s testing to the specific use case, and the freshness of the vendor’s evidence is itself part of the assurance documentation.

Audit rights and ongoing vendor oversight. Vendor leverage is sustained by ongoing oversight, not by one-time qualification. The audit rights, change notification commitments, and ongoing vendor performance review are integral to the vendor leverage posture.

Limitation on vendor leverage for novel or critical functions. For functions where the vendor evidence is structurally limited (novel use cases, customizations, integration-specific behavior) or where the consequence of failure is severe, the quality team performs independent validation rather than relying on vendor evidence. The discipline of recognizing when vendor leverage is not appropriate is itself part of the maturity.

The ISPE March-April 2025 analysis of the CSA risk-based approach documents these patterns in detail and reinforces the maturing industry consensus on how vendor leverage operates defensibly under CSA.

The AI and SaMD Integration Question

One of the most substantive 2024-2026 developments in CSA practice is the integration question with AI and SaMD-adjacent validation requirements. The 2022 draft was scoped to production and quality system software, not to AI/ML-enabled systems. As AI use has matured in pharma and device manufacturing, the practical question has become: how does CSA’s risk-based assurance posture interact with the AI-specific validation expectations articulated in the FDA’s credibility framework guidance, the FDA/EMA Good AI Practice principles, and ISPE’s GAMP guide on AI?

The pattern emerging in industry practice. CSA principles apply to the software substrate; AI-specific validation applies to the AI components within that substrate. The two are complementary rather than competing, but the integration requires deliberate framework design.

For software that incorporates AI components in regulated workflows:

• The software substrate is validated under CSA principles, with risk-based testing scope calibrated to intended use
• The AI components within the software are validated under the FDA credibility framework or analogous AI-specific approach, with documented credibility evidence for the specific context of use
• The integration between the two — how the AI components are configured, monitored, and updated within the software substrate — is documented as part of both the CSA assurance package and the AI credibility evidence

This integration is not yet fully articulated in either the CSA guidance or the AI-specific guidances, and quality teams operating in this space are making operational decisions that will inform the next round of regulator guidance. As the ISPE GAMP Guide on Artificial Intelligence (published July 2025) and the joint FDA/EMA Good AI Practice principles mature, the integration patterns will likely be more explicitly addressed.

Inspection Readiness in 2026

The 2024-2026 inspection experience under CSA has produced learning that quality teams should be incorporating. Several inspector patterns have emerged:

Risk assessment documentation is probed substantively. Inspectors are increasingly familiar with the CSA framework and will probe whether the risk assessment that drives testing scope is rigorous or perfunctory. Quality teams whose risk assessment looks like a check-box exercise face uncomfortable inspection conversations.

Vendor qualification is examined for substance. Inspectors are increasingly distinguishing between meaningful vendor qualification and nominal vendor qualification. Teams that have done substantive vendor qualification work navigate inspections more readily than teams that have not.

Documentation alignment with the 2022 guidance terminology helps. Inspectors familiar with the CSA guidance can navigate documentation that uses the guidance’s vocabulary more readily than documentation that uses bespoke organizational terminology. The alignment is a small investment with disproportionate return.

Higher-risk uses receive more scrutiny. Inspectors apply proportional scrutiny: low-risk uses with light documentation receive limited probing, while high-risk uses with substantial documentation receive deep examination. This is consistent with the risk-based principle the guidance articulates, but quality teams should ensure that high-risk uses can withstand the deeper scrutiny.

Critical thinking evidence matters. The most common positive inspection finding under CSA is when the documentation clearly evidences the critical thinking that produced the validation scope decisions. The most common negative finding is when the documentation looks like the output of a process without evidence of substantive thinking. The distinction is real and inspectors are increasingly capable of making it.

Practical Actions for 2026

For quality leaders operating under CSA in 2026, several practical actions are well-supported by the 2024-2026 implementation experience.

Refresh risk tier classifications across the active validation portfolio. Risk classifications produced in 2023 or early 2024 often reflect early CSA implementation thinking. The 2026 baseline for what constitutes a defensible classification is higher; refreshing the classifications surfaces gaps before inspections do.

Audit vendor qualification documentation for substance. Nominal vendor qualification was common in early CSA implementation; the 2026 inspection baseline expects substantive qualification. Auditing the vendor qualification documentation across the portfolio and remediating the gaps is high-leverage work.

Document the CSA-AI integration explicitly for AI-incorporating software. For software that includes AI components, the integration between CSA assurance and AI-specific validation should be documented explicitly. The integration is the area where the documentation is most likely to be probed and where the regulatory expectations are most actively evolving.

Develop QA capability in unscripted testing methodology. Unscripted testing — exploratory, ad-hoc, error-guessing — is referenced in the 2022 guidance but is unfamiliar territory for many traditional CSV teams. Building genuine capability in unscripted testing methodology (not just documentation that names the approach) is a multi-month investment that produces substantial leverage.

Engage with industry working groups. ISPE, PDA, and other industry bodies are continuing to refine CSA implementation practice. Active engagement gives quality leaders access to peer learning and emerging consensus on patterns that work.

Plan for guidance finalization. The 2022 draft has not yet finalized as of May 2026. When it does finalize — likely during 2026 or 2027 — the operational guidance may shift. Quality teams that have built their CSA practice on the draft and are positioned to absorb finalization changes will be better placed than teams that have to substantially restructure their practice.

How CSA interacts with the broader GAMP 5 framework

An integration point worth understanding: CSA does not replace GAMP 5, despite occasional industry conversation suggesting it does. GAMP 5 remains the operational framework most pharma and device manufacturers use for computerized system validation, and CSA principles are best understood as augmenting GAMP 5 with the FDA’s explicit risk-based posture rather than replacing the GAMP 5 structure.

Quality teams that have evolved their GAMP 5-based CSV practices to incorporate CSA principles — risk-based scope, vendor leverage, lighter documentation for low-risk uses — produce a more coherent operational framework than teams that try to operate parallel CSA and GAMP 5 practices. The 2024-2026 maturation has been substantially about this integration, and the patterns that work treat CSA and GAMP 5 as complementary rather than competing.

The role of CSA in the broader GxP modernization conversation

A final strategic point. CSA is one of several regulator-led modernization initiatives that are collectively reshaping GxP practice in 2026. The FDA’s posture on AI in regulated workflows, the EMA’s Annex 22 work, ICH M15 on model-informed drug development, and the broader international convergence on AI in pharma are all part of the same modernization trajectory. CSA’s risk-based assurance posture is the substrate on which much of the AI-specific work sits.

Quality leaders thinking strategically about the next two to three years of GxP practice should be reading CSA implementation maturity as one signal of how their organization will absorb the broader modernization. Organizations that have matured their CSA practice substantively are better positioned to absorb the AI-specific guidances than organizations whose CSV practice still looks like 2018. The CSA work is not just about software validation; it is about whether the organization’s validation discipline can adapt to the broader regulatory direction the agencies are clearly heading in.

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