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How to fulfill PFMEA "requirement" column?

#1
Dear good people,

I'm looking for your opinion.
We are doing a review in our PFMEA and Control Plan, we want to ensure all PFMEA and Control Plan have a linkage.

What we understand are
1. "Requirement" in PFMEA may be become "Product Characteristic" in control plan. and "Cause" in PFMEA may be become "Process Characteristic" in control plan.
2. "Requirement" is contain with what process intend to build. or defined as "Product Characteristic"
3. We start to build flow chart before we build PFMEA.

The current condition is,
1. We define our PFMEA for process A as
  • Material Preparation - This process is to prepare material as specification
    • Requirement : Material not expired
    • Failure : Material expired
    • Cause : Operator using expired material
    • Effects : Product easy to separate and explode
  • Machine Preparation - This process is to prepare machine condition as specification
    • Requirement : Drum circum
    • Failure : Drum circum too big
    • Cause : Operator using wrong drum circum
    • Effect : Product outer circum not meet with regulation
  • Assembly
  • Final Check - This process is to check product outer circum after assembly
    • Requirement : Product outer circum comply with standard
    • Failure : Product outer circum too big
    • Cause : Operator using wrong drum circum
    • Effect : Product outer circum not meet with regulation
  • Storage

2. We define our Control Plan as
  • Material Preparation
    • Product Characteristic : Material identification
  • Machine Preparation
    • Process Characteristic : Drum circum
  • Assembly
  • Final Check
    • Product Characteristic : Product outer circum
  • Storage
Process A have product outer circum as product requirement, which 100% had impact from drum circum. But, we can see in material preparation we did not have consistency with "Requirement" may be "Product Characteristics".

I already asked this idea for many times to different person and the answer always different with :

a. "Requirement" is both process characteristic and product characteristics. You can put "drum width, pressure, temperature, production volume, separate the non conformance, set up, etc" in requirement.
b. "Requirement" is only product characteristic. We need to think what "product characteristic" in macro process A that related in every micro process.
c. "Requirement" is both process characteristic and product characteristic. During preparation is process characteristic, during inspection is process characteristic. Except that you should define as product characteristics.

What do you think about this? Which one you think is more acceptable. Or maybe you have better theory. Thank you
 

Sebastian

Really trusted?
Trusted
#2
Initially "Requirement" column is only for product characteristics taken from drawing or other document defying product specification.
Sometimes drawing specifies also process characteristics, e.g., tightening torque.

You need to determine cause of failure using e.g. 5 why.

Initial answer is recorded in "Failure cause" column and later in detection columns there are presented prevention/detection actions aimed on failure or/and its causes.

Then you can move initial answer from "Failure cause" column to "Requirement" column and ask second time "Why?".
You keep asking until you determine root cause.

This way you record step-by-step your know-how and it can be available to all interested parties in your organization.
Do you get my point?
 
Last edited:

Johnnymo62

Haste Makes Waste
#3
The way I have done it is that each step of the process flow has at last one requirement, maybe more. If it's a step about making, or moving the parts it's a process requirement. If it's a measurement or verifying anything on the drawing it's a product requirement.

It may not be correct but I have never had an auditor or customer complain.
 

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