A Failing APS: The Nightmare of Every Sterile Department
A Practical Approach to Root Cause Analysis
A failing aseptic process simulation (APS) is the nightmare of every sterile manufacturing department. The moment the broth turns turbid, alarm bells start ringing across the organization.
Production and quality teams immediately escalate the issue. Sterile manufacturing leaders gather to assess the situation and urgent decisions are made. Often, the suites where the APS was performed are quarantined. Commercial sterile production may continue only until the batches currently in progress are completed, but no new batches are started until the root cause of the positive APS result is identified.
A dedicated “war room” is typically established, and a team of subject matter experts (SMEs) and quality representatives is assembled to begin the investigation.
Why It Matters
A failed APS has immediate and significant operational and regulatory consequences.
First, until a root cause has been identified, all sterile products are considered within scope of the investigation. As a result, product release is halted.
Second, regulatory authorities must be notified. In Belgium, for example, companies are required to inform the Federal Agency for Medicines and Health Products that production of the affected product has been temporarily suspended due to a failed APS and that a root cause investigation is ongoing.
Finally, prolonged investigations can lead to production downtime, supply risks, regulatory scrutiny, and increased operational costs. For sterile manufacturers, the pressure to identify the true root cause quickly and accurately is therefore extremely high.
Typical Pitfalls During APS Investigations
In practice, several challenges often complicate root cause investigations after a failed APS.
Unclear investigation scope: At the start of the investigation, the scope is often broad. If the investigation is not structured, teams may struggle to determine which products, processes, or production lines are truly affected.
Lack of cross-functional expertise: A comprehensive root cause analysis requires expertise from multiple disciplines, including microbiology, engineering, quality, and production. Without the right expertise, investigations can overlook critical factors.
Insufficient environmental data: Investigations sometimes lack supporting environmental monitoring data or airflow analysis, making it difficult to identify the true contamination source.
Delayed coordination and decision-making: Without structured meetings and clear responsibilities, investigations can lose momentum and corrective actions may be delayed.
Normec Advipro’s Approach in Practice
At Normec Advipro, we typically support sterile manufacturers with a structured and multidisciplinary approach to root cause analysis.
- 1
Rapid investigation setup
A structured investigation framework is established immediately. SMEs and quality representatives form a dedicated investigation team, often working from a centralized “war room”.
- 2
Broad initial scope assessment
At the start of the investigation, all sterile products are considered within scope until sufficient evidence allows the investigation to be narrowed.
- 3
Structured investigation management
Daily tier-style meetings help monitor progress, track action items, and ensure accountability across teams.
- 4
Technical investigation support
Technical investigations focus on identifying potential contamination pathways. Environmental monitoring data is reviewed and, where relevant, additional studies such as Air Visualization Studies (AVS) and microbial sampling are performed.
As evidence is gathered, the investigation scope can gradually be refined, allowing certain production lines to resume operations while corrective and preventive actions (CAPAs) are implemented.
- 5
Restarting Production
Before commercial production can restart, several conditions must be met.
Three consecutive successful APS runs should be completed to demonstrate that the process is back under control. In addition, regulatory authorities should provide a positive recommendation before commercial manufacturing resumes.
Practical Recommendations
Based on experience supporting sterile manufacturers, several practices can significantly improve APS investigations.
Start the root cause analysis immediately: Rapid mobilization of the investigation team helps reduce production downtime and ensures critical data is captured while events are still fresh.
Use structured investigation management: Daily progress meetings and clear action tracking help maintain momentum and avoid delays.
Include airflow and environmental studies where relevant: Airflow visualization and microbial sampling can reveal contamination pathways that are not immediately visible.
Final Thoughts
A structured investigation approach, supported by the right expertise and technical tools, can significantly improve both the speed and quality of root cause analysis following a failed APS.
If your organization is facing a complex sterile manufacturing investigation, the experienced experts at Normec Advipro can support you with investigation management, technical studies, and the implementation of corrective actions. Normec Advipro’s MoVE team also provides support with Air Visualization Studies (AVS), environmental monitoring.
Meet our Normec expert:
Evelien Fossépré
Project Engineer
Evelien Fossépré is a consultant at Normec Advipro specializing in sterile manufacturing and contamination control. She is a certified QP with manager experience in packaging and sterile compounding and has a QA background in the sterile department. She also has experience with supporting pharmaceutical manufacturers in investigations and validation activities, she helps companies strengthen compliance and operational reliability.
