What is exactly the root cause?

[qualprod]

Hi everybody

I come with this issue, maybe it was questioned a lot of times, however have not found something
convincing for me, in the analysis I face doubts not easy to be solved in my understanding.
I´ll share a case hoping yor are able to help me.
in trying to find the root cause in a CA because of defective product delivered to the customer.
Considering, Man.Material, procedures,measurement, environment and machine.
After analyzing each, we found two causes.
1-Wrong instructions of product into the work order by the sales responible
2-Missed inspection at certain step of the production.

From here, I could think by a 5w in (1) why wrong... because didn´t know well the machines to choose the right machine , why.., because, didn´t have a training, why didn´t have training.., because, nobody was aware of his competency to develop this job or??.
for the (2), by using 5w, why, because worker, didn´t know the instructions (didn´t know he had to call the inspector at that step), why.. because was not fully trained in that production, why.... because nobody took care about the progress of his training. or??

Ok, I coud think, is enough with this cause (1), and from here to define action plans and finally to evaluate the effectiveness.

Could I say this is the only root cause (1) and the (2) not to be addressed, because if the (1) hasn´t been happened, the (2) would´have not been happened.
or could I suppose both are valid and for both I have to define action plans?
Or the point is, to find root causes of any problem happened in the reject of customer

Also in the final root case in both cases, I have some doubts.

I´m confused, please give your advice.

Thanks

 

[Jim Wynne]

I´ll share a case hoping yor are able to help me.
in trying to find the root cause in a CA because of defective product delivered to the customer.

Is this an actual current issue you're facing, or a hypothetical situation? If it's an actual case, you need to provide enough information for us to be able to help you. What is the product and the nature of the defect(s)? Is this a recurring problem?

 

[Tagin]

From here, I could think by a 5w in (1) why wrong... because didn´t know well the machines to choose the right machine , why.., because, didn´t have a training, why didn´t have training.., because, nobody was aware of his competency to develop this job or??.
for the (2), by using 5w, why, because worker, didn´t know the instructions (didn´t know he had to call the inspector at that step), why.. because was not fully trained in that production, why.... because nobody took care about the progress of his training. or??

Both of these point to a single area: 7.2 Competence

It looks as though management has not performed (or inadequately performed) 7.2 a-d for these job roles, or at least not adequately.

But in addition, your references to 'nobody' suggest that management has failed to assign responsibility (5.3) to someone to monitor 1) the training requirements for these roles and 2) whether employees have been trained to the requirements and 3) have demonstrated competence.

The more I think about 'root cause' these days, I think the idea of a single root cause is overly simplistic. The QMS is an organized, interconnected web of a system, and not a simple linear sequence of events.

 

[Jim Wynne]

The more I think about 'root cause' these days, I think the idea of a single root cause is overly simplistic. The QMS is an organized, interconnected web of a system, and not a simple linear sequence of events.

A QMS is a system of linear processes. Processes often cross department boundaries, but that doesn't mean that the idea of a single cause is simplistic. The goal is to identify some feature or step in the process which if corrected would prevent the thing from happening again, and not to think of it as an amorphous blob without identifiable constituent parts.

 

[Tagin]

A QMS is a system of linear processes. Processes often cross department boundaries, but that doesn't mean that the idea of a single cause is simplistic. The goal is to identify some feature or step in the process which if corrected would prevent the thing from happening again, and not to think of it as an amorphous blob without identifiable constituent parts.

We disagree. At the least, I see a 9001 QMS as a cyclical PDCA, not linear. Within that, processes are themselves typically PDCA cycles in nature, if not in documentation. Nowhere did I say or imply that it was an amorphous blob without identifiable constituent parts.

 

[Jim Wynne]

We disagree. At the least, I see a 9001 QMS as a cyclical PDCA, not linear. Within that, processes are themselves typically PDCA cycles in nature, if not in documentation. Nowhere did I say or imply that it was an amorphous blob without identifiable constituent parts.

If QMS processes were not linear, it wouldn't be possible to create a process flow diagram. In terms of control, QMS processes MUST be linear.

 

[qualprod]

Is this an actual current issue you're facing, or a hypothetical situation? If it's an actual case, you need to provide enough information for us to be able to help you. What is the product and the nature of the defect(s)? Is this a recurring problem?

Thanks Jim

Is somewhat recurring.
Is a real case.

The responsible who catches the customert needs, develops the work order, based on
type of machine ,its capacity, cost/hour, the handling of sheets, machine allowable dimensions to produce parts, etc.
He needs to understand perfectly all this data before releasing the work order to production.
This time, assigned other similar machine not the correct one, for this job.

Operators follow the instructions recommended in the work order, diemensions of product, tolerances,what machine have to be used
for printing, what type of process: cutting, punching, type of packaging, type of box, etc.

Due to this, the product resulted with some defects because was fabricated in that "similar machine".

The products is comprised of several steps, printing, cutting, bending, packing and delivery.
In each step product is verified against specifications, but after bending, the worker simply, didn´t follow
the instructions in the procedure of production, where is clearly stated "when product is finished in eachs step, have to call the Inspector
to verify quality of product.

Questioned why this happened, just told us, I was trained quickly, didn´t know in detail the procedures, so I thought that at this step
checking was not neccessary, I supposed will be checked in the next step.

Normally final checking is not done, because over the time has been enough this type of checkings.
Going to the original question, in this case: what is recommended to do?

Just to consider the first cause? considering that if first would not have happened, I wouldn´t have to worry for the second?

Who is authority to approve that root cause (1) is enough or have to be both?

Thanks

 

[lanley liao]

In fact, these belong to the process-based of management, which so-called process approach. you shall find out the root cause from the gap of the management system. this involves three aspects: planning——implement——checking. and then identified which stages have been a problem. This problem, analyzed from material, procedures, measurement, environment, and machine. Generally speaking, modified the corresponding document rules and organized the training related to the department head and staff. FYI

 

[Jim Wynne]

The responsible who catches the customert needs, develops the work order, based on
type of machine ,its capacity, cost/hour, the handling of sheets, machine allowable dimensions to produce parts, etc.
He needs to understand perfectly all this data before releasing the work order to production.
This time, assigned other similar machine not the correct one, for this job.

Taking this and some of your previous posts, there seems to be a pattern of incompetence. In this case, it seems fairly obvious that there should be standardized routers for your various jobs, such that one person doesn't have to create one every time a job is run. The problem seems to go deeper than that, though.

 

[Jen Kirley]

I agree with Jim. This is too important to rely on a relatively recently trained employee to "understand perfectly." How will he understand the various machines' capabilities perfectly? Do you have a guideline? This seems to me to be about the planning process.

It is reasonable to limit machines to processing determined materials requiring particular tolerances. Their performance capabilities can be understood over time and known performance. Machine #1 is capable of handling to tolerance of X for ABC material(s), and Machine #2 is capable of processing to a tolerance of Y for XYZ material(s). Forming a matrix of this data would help you avoid having to re-learn all of this whenever the planner eventually leaves (and we all leave sometime, for one reason or another) and could support both accuracy and production planning for a minimum of process "bottle necks." This type of document would ideally be protected against loss and unauthorized change, though it does not need to be controlled in the same way as a procedure - signatures for updates, revision numbers etc.

I also agree with Lanley, it seems sensible to have a step in the planning process for an experienced person to check the planning. A signature and date spot on the work order would help define this process step and help ensure it is being done - as long as someone at some point is overseeing that, to ensure all responsible persons are providing their required inputs.