Discrepancy was noted in depyrogenation tunnel’s belt speed verification test.

This deviation case study is based on the belt speed verification test of sterilization and depyrogenation tunnel. Belt Speed test failed during operational qualification. We will see how to rectify, investigate this deviation/nonconformance.

1.0 Deviation Control No./ NCR No.:


2.0 Date:


3.0 Concern department:


4.0 Deviation related to:

Product/ Material/ Process/ Document / System / Facility / ✓ Equipment / Other

5.0 Area of Deviation:

Specification/ Labelling / Analysis / Shelf life / BMR/BPR / Process failure / ✓ Validation / Repacking / Batch release / Documentation / Stability / Other

6.0 Description of deviation/Nonconformance:

On dated 05/11/21, during operation qualification of depyrogenation tunnel third party found that conveyor belt speed verification test is fail against the acceptance criteria. Obtained result to the third-party during operational qualification is as per below:

Depyrogenation Tunnel, deviation example

7.0 Immediate Action:

Immediately informed to production, Quality Assurance and Engineering dept for the rectification of observed deviation. Production department immediately generate work order and handover to engineering dept.

The routine batch manufacturing activity is stopped till the rectification of the issue.

8.0 Justification of Immediate Action Plan:

Work order submitted to the engineering department for further action. Suggested immediate action for the initiated discrepancy is satisfactory.

9.0 Type of deviation:

Planned Deviation / Unplanned Deviation

10.0 Repetitive deviation:

Yes / ✓ No

11.0 Category of deviation:

✓ Major / Minor

12.0 Intimate to other departments:

Quality Control, Stores, Engineering, EHS, R&D, Regulatory Affairs, Administration, Corporate Quality Assurance etc.

13.0 Root Cause Analysis (RCA):

13.1 Following root cause analysis method should preferred for the investigation of the root cause:

  1. Is / Isn’t Analysis
  2. Ishikawa Diagram (Fishbone Diagram)
  3. Five why analysis

13.2 Is / Isn’t analysis:

Below is the investigation method:

Depyrogenation Tunnel, Deviation example, root cause analysis


Based on the analysis investigation team found that there is no other equipment suffering from the same issue.

13.3 Ishikawa Diagram (Fishbone Diagram):

13.3.1 Ishikawa analysis is performed by considering the 6 major categories such as Machine, Material, Man, Environment, Measurement and Method.

13.3.2 After Ishikawa analysis some cause is observed to the investigation team:

Ishikawa Diagram, root cause analysis, Deviation Depyrogenation tunnel
13.3.3 Machine   Technical Evaluation: After deviation found production dept generate work order and submitted to engineering dept. Engineering person found the conveyor belt speed observed higher than the set parameter. PLC (Program Logic Control) display showing the accurate belt speed i.e. 50/100 /140 mm/min but manually check the speed of belt then got results 63/114/163 mm/min. Finally, technical team concluded that issue is related with internal hardware function and it shall be rectified only by the vendor. Vendor performed the verification of tunnel belt speed and they found that Rowan card speed was higher than the actual speed shown in PLC. Hence, Rowan card was not aligned with the set speed. After rowan card alignment manually performed belt speed is matched with the displayed PLC result and found satisfactory.


Based on the evaluation, this issue might be occurred due to equipment working over the period of time hence, Rowan card alignment might be disturbed and lead to increase the speed of belt.  Verification of breakdown history: Verified Breakdown history of for last 12 months to identify whether any similar discrepancy identified in past, no discrepancy was observed in last 12 months.


No similar discrepancy was found in last 12 months.  Verification of previous requalification details: Periodic requalification data of depyrogenation tunnel verified. All parameter is included in the document. Results of the depyrogenation tunnel belt speed is recorded as per displayed PLC. There is no any provision for the physical/manual verification (distance travelled by belt in unit time) of the belt speed. If requalification protocol would have such provision, such type of discrepancy should be avoided.


As per investigation team concluded that there is no any provision for the physical/manual verification (distance travelled by belt in unit time) of the depyrogenation tunnel  belt speed.

13.3.4 Material

Material is not involved in the activity. So, this factor is not applicable for analysis.

13.3.5 Man Check the qualification and training record of all persons involved in the activity like routine operation, preventive maintenance. Take interview to identify any abnormality found during their work.


All person involve in respective activity are trained and qualified. No any abnormality found during the interview of persons.

13.3.6 Mother Nature / Environment

There is no environmental impact on observed deviation.

13.3.7 Measurement  Verification of last Preventive maintenance details. Preventive maintenance is being performed is with every two months of frequency. Checked all the parameters of preventive maintenance like misalignment of gear box of main conveyor belt, chain, belt roller bearing, all-electric connection and found satisfactory.


During the verification of last preventive maintenance, no discrepancy found related to the equipment check points.

13.3.8 Method  Verification of standard procedure for the depyrogenation tunnel belt speed: Standard procedure for the speed verification test is reviewed and performed as per the following standard procedure: For this test, run the empty conveyor belt with routine temperature. Mark the tunnel conveyor belt. Set the belt conveyor speed to 50/100/140 mm/min. Start the tunnel for 1 minute. Simultaneously start the stopwatch. After 1 minute measure the distance between the markings using calibrated measuring scale. Acceptance criteria: The measured value for the tunnel conveyor speed (50 mm/min) is within ± 10 % of the adjusted set value. The measured value for the tunnel conveyor speed (100, 140 mm/min.) is within ± 5 % of the adjusted set value. Following results are observed during performing the activity:

Depyrogenation Tunnel, deviation example


Based on the verification of the standard procedure for the belt speed verification, there is no gap was found against the defined standard procedure, but test was found failed because PLC displayed speed not match with actual speed obtained.

13.4 Five-why analysis method:

Performing 5-why analysis method to identify the root cause.

depyrogenation tunnel, 5 why, root cause analysis, deviation


After completion of 5 why analysis investigation team noted that the nonconformance might be occurred due to ageing factor or over working of equipment.

13.5    Final conclusion of Root Cause Analysis (RCA):

13.5.1 Equipment:

Rowan card alignment was disturbed due to over period of time or ageing factor.

13.5.2 Method:

In method there is no provision to record distance travelled by belt in unit time. Hence, lack of information available in standard procedure. Which provide less guidance for how to test perform.

13.6 Impact Evaluation:

13.6.1 Identify the impact on previously manufactured batches: Previously manufactured all baches are review for BET and sterility test and all baches are comply the specification limit. Based on this reviewed document, it is confirmed that there are no any abnormal results recorded and no any impact on product quality found.

14.0 Corrective and Preventive action

14.1 Machine

14.1.1 Based on the identified root cause depyrogenation tunnel belt speed (rowan card) alignment is performed by the vendor and it is working properly.

14.2 Method

14.2.1 Requalification document is revised to incorporate the provision for record distance travelled by belt in unit time (Manually) and training will be provide to all concern persons regarding the method / document changed.

14.2.2 Based on the corrective action there is no need of preventive action. So, no any preventive recommended for this deviation.

15.0 Impact of CAPA:

Other system / Layout / Regulatory / Stability / Other batches / Process / Validation / Utility/ ✓Equipment / ✓ Documentation  / Other /  N/A 

16.0 Implementation of CAPA:

Implementation of CAPA is verified by QA and CAPA team

17.0 Effectiveness check:

✓ Required / Not required

18.0 Effectiveness check failure evaluation:

18.1 Criteria: After the implementation of CAPA, next periodic requalification record will be verified for the tunnel belt speed verification test.

18.2 Rational: Collect enough amount of data for verification of effectiveness check after requalification.

18.3 Acceptance Criteria: No similar issue should be reported with same cause.

19.0 Refer the following formats:

19.1 Deviation Form

19.2 CAPA Form

20. Abbreviation:

DC – Deviation Control

PLC – Program Logic Control

BET – Bacterial Endotoxin Test

CAPA – Corrective Action & Preventive Action


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