1.0 Objective
To provide a guideline for conducting “Failure Mode and effect Analysis” and “Root Cause Analysis”.
2.0 Scope
This SOP is applicable in equipment / process and for investigating the root causes of product complaints, OOS, deviations or problems.
3.0 Responsibility
Production, Quality Assurance, Unit Head and Corporate Quality Assurance.
4.0 Accountability
QA Head shall be accountable for implementation of this SOP.
5.0 Abbreviations and Definitions
OOS : Out of specification
BMR : Batch Manufacturing Record
BPR : Batch Packing Record
Sr. No. : Serial Number
6.0 Procedure
Failure Mode and Effect Analysis (FMEA) Vs Root cause analysis (RCA):
| Sr. No. | FMEA | RCA |
|
1 |
Prospective, Proactive
Focus : Failure prevention |
Reactive
Focus : Failure detection |
| 2 | Used for changes or modification in equipment, process | Used for product complaints, OOS, unplanned deviation, recalls. |
| 3 | Choose topic for evaluation of failure modes prior to its implementation | Analyse underlying cause on occurrence of a failure through a series of ‘WHY’ questions |
| 4 | ‘Contributory factors’ for potential failure modes are its implementation. | Causes of problems are investigated what went wrong? |
| 5 | Goal: Evaluate impact of changes and decrease the ‘RPN’ | Goal: Preventing recurrence of problem |
| 6 | Includes detestability in evaluation | Develop ways to defect and fix a problem. |
6.1 FAILURE MODE AND EFFECT ANALYSIS: In conducting FMEA, the basic steps are:
6.1.1 Identify the process to be examined.
6.1.2 Assign FMEA team members and team leader.
6.1.3 Explain the methodology to the team.
6.1.4 Prepare the flow chart or detailed process flow of the process under analysis. All steps in the process should be included.
6.1.5 Designate which of the steps in the process constitute “Functions” and identify elements of variation in equipment, methods, materials, control and measurement.
6.1.6 Determine which functions represent potential “Failure Modes” or points of potential failure and record in Annexure————–.
6.1.7 Determine the worst potential “Effect” or consequences of each of the failure modes.
6.1.8 Determine the “Contributory Factors” for each failure mode. (Note use of the tem “Contributory Factor” rather than “Cause”).
6.1.9 Identify any “Controls” in the process. Controls are components of the process which (a) reduce the likelihood of a contributory factor or a failure mode, (b) reduce the severity of an effect, or (c) detect the occurrence of a failure Mode or Contributory Factor before it leads to the adverse outcome (Effect). Examples of control measures are: Standard Operating Procedures, BMR BPR, Validation, In-process controls and alarm systems.
6.1.10 Rate the severity of each (on a scale of 1-5, 1: no effect on output, 2: minor effect, 3: moderate effect, 4: serious effect, 5: hazardous effect). The impacts of controls that improve the severity of an effect are reflected in this rating as well.
6.1.11 Rate the occurrence (likelihood) of each contributory factor (on a scale 1-5, 1: failure unlikely, 2: remote failure, 3: occasional failure, 4: high failure, 5: failures certain). The impacts of controls that reduce the likelihood of occurrence of a failure mode or contributory factor are reflected in this rating as well.
6.1.12 Based on the control measures, rate the effectiveness of each “Detection Control” (on a scale of 1-5, 1: Flawless detection system, 2: well detect failure, 3: might detect failure, 4: almost certain not to detect failure, 5: lack of detection control).
6.1.13 Multiply the three ratings by one another for each ‘Contributory Factors’ according to the Risk Priority Numbers.
Note: Pareto chart with the traditional 80% rule to determine which contributory factors should be addressed first may be used.
6.1.14 The ‘PRN’ determines the criticality of the failure mode and helps determine whether the risk of failure should be accepted (do nothing about the potential failure), controlled (take action to enhance detection or reduce the risk of the potential failure) or eliminated (prevent the potential failure).
6.1.15 Using FMEA tool:
6.1.15.1 FMEA should be used to analyze the current process and evaluate the potential impact of change under consideration. For Example: New equipment / process, major modification. Calculate the estimated RPN each time you consider a change to the process, evaluate the impact of the change. If RPN is high, then priority should be given to such items and based on the current control measures, action plan for additional measures required should be made (Annexure————–). Priority should also give to items with high severity rate.
6.1.15.2 Examples of risk that may be identified include, but are not limited to:
- Risk to manufacturing equipment such as equipment downtime, equipment damage, cost of replacing equipment parts and any potential for injury.
- Quality of the finished product.
- Incorrect composition.
- Raw material / Packing material errors.
6.1.15.3 Examples of mitigation strategies that may be used to modify risk levels (RPN) are:
- Modify process design such as additional data verification checks.
- Introduce external procedures such as double checking of counter possible failures.
- Increase the scope and level of testing applied during various stages of validation.
Note: Validation and in-process control requirement should be reviewed.
6.1.15.4 ‘RPN’ should be recalculated periodically, once in two years to see if the changes made are leading to an improvement over time by comparing RPN. A reduction in the RPN value indicates an improvement.
Note: ‘RPN’ is a measure for comparison within one process only.
6.1.15.5 Allot an FMEA number to identify a process or equipment having similar principle.
Note: FMEA is often a standard tool used in the development of new products / processes.
6.1.15.6 Annexure———————— shows the FMEA flow diagram.
6.2 ROOT CAUSE ANALYSIS: the root cause analysis is aimed at first generating possible root causes for the problem and then narrowing focus onto the most probable cause for the problem. In conducting root cause analysis (RCA), fish bone diagram / Ishikawa diagram should be used as the analysis tool. Steps for constructing a fish bone diagram are:
6.2.1 Define your problem from the following sources and assign RCA team members:
INTERNAL: OOS reports, self inspection, atypical results, trend analysis, FMEA, annual product review.
EXTERNAL: Market complaints, field service reports, quality audit reports.
Root cause analysis should involve those who are most familiar with the processes and systems and include participation of the Department Head.
6.2.2 Draw the fishbone diagram as follows:
Write the problem on the far right side of your diagram and draw a long horizontal arrow pointing towards it.
- From the horizontal arrow, you will be able to branch off major and minor causes of this problem. First you must identify the most significant causes, or potential causes for the problem. These will form the main branches from the “backbone arrow”. You may start with a few and continue to brainstorm and define about 6-8 main categories.
- From these, you can continue to brainstorm in more details, and explore why these factors may be problems. It is best to develop as many hypotheses as possible so that no potential root cause is overlooked.
6.2.3 Label each “bone of the fish”. The major categories utilized are:
Methods, machines, materials, people, procedure, process, suppliers, systems, measurement, personnel, environment, controls and monitoring.
- The team should identify each process step; identify elements of variation in equipment, measurement, personnel, environment, materials, methods, environment, controls and monitoring.
- The term should ask a series of “whys”, repeat this with each major cause to produce sub causes. Continue asking “Why” and classify them on the diagram. If an idea fits on more than one branch place it on both. Be sure that the causes have a direct, logical relationship to the problem or effect stated at the head of the fish bone. Continue until a potential root cause has been identified. A root cause is one that can explain the “effect” and if removed would eliminate the problem.
- Analyse the results of the fishbone after members agree that an adequate amount of detail has been provided under each major category.
- Look for those items that appear in more that one category. These become the “most likely causes”.
- From those items identified as the “most likely causes” the team should reach a consensus using the team’s best collective judgment on listing those items being “most probable cause”.
- The team should go through all the steps to determine occurrence – Root cause (why the problem occurred ?) and then go through the steps again to determine the detection – Root cause (why the problem wasn’t detected?).
- Record the possible causes against each category and the possible action for the causes in Annexure————-. Priorities the causes and identify the root cause.
- Take corrective and preventative action as per ————————-.
7.0 References:
CQA ——- : Corrective and Preventative Action (CAPA).
8.0 Safety & Precautions:
Not Applicable.
9.0 History
| Date | Revision Number | Reason for Revision |
| – | – | New SOP |
