D5 of 8D clarification, how to verify root cause

[qualprod]

Hello everybody

In doing an 8D method to solve a problem, I found difficulty to ensure what is required, according to this definition.

• D5: Choose and verify permanent corrections (PCs) for problem/nonconformity - Through preproduction programs, quantitatively confirm that the selected correction will resolve the problem for the customer.

Example: Suppose is having mechanical parts with defects.
and the root cause was a capacity of a motor.
to verify this , Tests should be done, simulations, etc.
Well, at verification, is possible to use the new motor and can be sure it works, now product is ok, so can continue to D6.

But in the case that a root cause is lack of training for an operator, how to ensure if this will work?
how to simulate or do a pre-testing?
To train this operator and wait until works?[ this will take a long time , weeks or months and the CA, have to be solved quickly,
or by having evidence of similar trainings with other people?

I understand this is previous to D6, where the permanent actions have to be implemented.
Any idea?

Thanks

 

[Johnny Quality]

qualprod,

Why was the operator lacking training?

 

[Miner]

If the root cause is truly training, you could verify this by testing operators post-training to make sure they actually understand.

 

[qualprod]

If the root cause is truly training, you could verify this by testing operators post-training to make sure they actually understand.

Miner
But this may take too long, will the 8D analysis, has to wait like that to be finished? weeks or maybe months?
Because, the planning : to wait the training is available with the external supplier, to send people, to have the training
, to wait until this operator works, to ensure such training eliminated the root cause?

 

[Jim Wynne]

Miner
But this may take too long, will the 8D analysis, has to wait like that to be finished? weeks or maybe months?
Because, the planning : to wait the training is available with the external supplier, to send people, to have the training
, to wait until this operator works, to ensure such training eliminated the root cause?

First, if this is an 8D that you're doing for a customer, the customer is likely going to ask you why an untrained operator was given the opportunity to mess something up. Also, corrective action takes as long as it takes. If, for example, you need a production run to verify the efficacy of the action(s) taken, and the production run won't happen until sometime in relatively distant future, then the 8D should be left open until then. It's often the case that customers don't understand this, or don't care and just want to close out things on their end whether or not the response makes sense.

 

[qualprod]

First, if this is an 8D that you're doing for a customer, the customer is likely going to ask you why an untrained operator was given the opportunity to mess something up. Also, corrective action takes as long as it takes. If, for example, you need a production run to verify the efficacy of the action(s) taken, and the production run won't happen until sometime in relatively distant future, then the 8D should be left open until then. It's often the case that customers don't understand this, or don't care and just want to close out things on their end whether or not the response makes sense.

I agree with you, to prove the actions were efective, this may take too long, but this is is a requirement in 6D.
In 5D, as I understand is to identify the root cause, and how to prove by simulation, testings, that this root cause will eliminate the problem.
or am I misinterpreting the requirement?
Please shed some light on me.

 

[Bev D]

Perhaps this is a language thing but let’s clarify that the means that are used to verify that the identified root cause is in fact the root cause you may use any of several means depending on what is appropriate - you do not have to use all of the suggested means. So you don’t always have to use simulation. Essentially what you have to do is turn the cause ‘on and off’ and ensure that the Problem is turned on and off.

Second your example of lack of operator training is simply NOT EVER a ROOT cause. A root cause is actionable such that reducing or eliminating or countering it teh problem wil not recur in the future. So Jim’s question is getting at exactly that issue.

 

[Jim Wynne]

I agree with you, to prove the actions were efective, this may take too long, but this is is a requirement in 6D.
In 5D, as I understand is to identify the root cause, and how to prove by simulation, testings, that this root cause will eliminate the problem.
or am I misinterpreting the requirement?
Please shed some light on me.

I don't know where your 8D form came from, but this bit makes no sense:

• D5: Choose and verify permanent corrections (PCs) for problem/nonconformity - Through preproduction programs, quantitatively confirm that the selected correction will resolve the problem for the customer.

I don't know what's meant by "preproduction programs." It can't be preproduction if a production problem has already occurred. I also don't know what "quantitatively" means in this context. In any event, if you need production in order to verify the efficacy of the correction, you need to wait until production happens.

 

[qualprod]

actionable

I don't know where your 8D form came from, but this bit makes no sense:

• D5: Choose and verify permanent corrections (PCs) for problem/nonconformity - Through preproduction programs, quantitatively confirm that the selected correction will resolve the problem for the customer.

I don't know what's meant by "preproduction programs." It can't be preproduction if a production problem has already occurred. I also don't know what "quantitatively" means in this context. In any event, if you need production in order to verify the efficacy of the correction, you need to wait until production happens.

I got it from here:

What is 8D? Eight Disciplines Problem Solving Process | ASQ

 

[qualprod]

I got it from here:

What is 8D? Eight Disciplines Problem Solving Process | ASQ

Regarding to verify by pre -testing.

This is an additional source:

Taken form here:
8D – Lean Manufacturing and Six Sigma Definitions

D5: Verify Permanent Solutions: Collect data to confirm that the possible solutions will actually resolve the problem. Perform on a small-scale or “pilot” project first