Process FMEA (PFMEA) vs. Equipment FMEA (EFMEA) Differences

[Yew Jin]

Hi guys,

1. What is the difference between the process FMEA and equipment FMEA?
(equipment is refer to the semi or fully automation)

2. How we want to do if there is overlapping on failure causes and effect when we implement these 2 FMEA? (When using the semi auto machine for a process) - some cases we confuse whether it is due to process or it is due to equipment.

3. If we go through on current control - prevention and detection, the team is loss especially when we did the equipment FMEA. Some of the member confuse by the term used, prevention = error proofing?

4. Is there any method to help us go smoothly when in the process of rating on the severity, occurance and detection? Most of the time the team member do not know how to rate with the existing control. This is very hard time in the whole FMEA implementation.

5. The team here set the priority of the action in 2 criteria,
a) RPN > 100
b) severity X detection = 81
I disagree on the b) as we should take action if there is any severity above 8 even the detection is high.

Please help!
:truce:

 

[The Taz!]

Re: Process FMEA vs Equipment FMEA

Hi. . . If I understand you correctly, you are developing a PFMEA for the process (Which includes the machine's cause/effect) and one for the machine itself.

Your PFMEA should include failure modes attributed to the machine/equipment. Your machine FMEA might include items such as periodic verification/validation of controls and sensors, and PM requirements that may prevent the failure modes found on the Process FMEA. It will also address PM issues to prevent downtime and maximize uptime. All can be included on the Process FMEA, but in doing a Machine FMEA, I think you will need to do one prior to actually selecting a specific piece of equipment because the equipment will need to meet all requirements for the product and process.

What I am saying amounts to using a PFMEA risk assessment to determine if a specific piece of production equipmewnt meets all criteria, and has the abilty to minimize the risks associated with the process. Also, as I stated earlier, what and when to review for PM purposes.

I hope I answered your question. . . with a FMEA, you only get out of it what you put into it.

 

[Miner]

Re: Process FMEA vs Equipment FMEA

1) Here are definitions from the Cove:

Types of Automotive FMEAs
Machinery FMEA – is used to analyze low-volume specialty machinery (equipment and tools), that allows for customized selection of component parts, machine structure, tooling, bearings, coolants, etc.
º Focuses on designs that improve the reliability and maintainability of the machinery for long-term plant usage.
º Considers preventive maintenance as a control to ensure reliability.
º Considers limited volume, customized machinery where large scale testing of a number of machines is impractical prior to production and manufacture of the machine.
º Considers parts that can be selected for use in the machine, where reliability data is available or can be obtained before production use.
Concept FMEA – is used to analyze concepts for systems and subsystems in the early stages.
° Focuses on potential failure modes associated with the functions of a concept proposal caused by design decisions that introduce deficiencies.
° Includes the interaction of multiple systems, and interactions between the elements of a system at concept stages.
° Would apply to all new machinery concepts that have never been done before, all new plant machinery layout, new architecture for machinery, etc.)
System FMEA – is used to analyze planned / proposed systems.
° Intended to transform an operational need into a description of system performance parameters and system configuration through the use of an interactive process of functional analysis, synthesis, optimization, design, test, and evaluation.
Design FMEA – is used to analyze products, high volume tools or standard machines, machine components, standard production tooling, etc., before they are released to production.
° Focuses on potential failure modes of products caused by design deficiencies.
° Focuses on parts that can be prototyped and tested or modeled before high volume production of the product is launched.
Process FMEA – is used to analyze manufacturing and assembly processes.
° Focuses on potential product failure modes caused by manufacturing or assembly process deficiencies.
° Useful in analyzing process steps that can influence the design of machinery, including selection of appropriate tooling and machinery component parts.

2) The goals of the two FMEAs are different and should be used for different reasons, so there should be little overlap.

3) Prevention is a control that detects a Cause before the defect has been produced. Detection detects the failure after it has been created.

4) Create your own rating scales with clear, specific definition for each. Base it on your existing controls, knowledge of occurrences and actual severities that you have seen.

5) I have seen the following:
Priority 1: Severity = 9 or 10
Priority 2: Severity X Occurrence = ##
Priority 3: S x O x D > ###

 

[AndyJP - 2012]

Re: Process FMEA vs. Equipment FMEA Differences

Miner has hit it on the head.

The simple prioroty is anything with a severity of a 9 or 10 you do first as a corrective action is mandated as it invloves safety. Then SxO with severity of 5 and above and an occurance of 5 and above mandate a corrective action. Then and only then look at RPN. To be RPN fixated is to be a fool!

 

[Marc]

Re: Process FMEA vs Equipment FMEA

Also see:

How to develop an Equipment / Machinery FMEA - Remember the key word: Predictive
and
Machine failure defects due to no/poor maintenance for FMEA

They're oldies, but still relevent.

 

[ralphsulser]

Re: Process FMEA vs. Equipment FMEA Differences

Miner has hit it on the head.

Then and only then look at RPN. To be RPN fixated is to be a fool!

Apparently some of the B3 have not become aware of this. ;-)

 

[Ajit Basrur]

Re: Process FMEA vs. Equipment FMEA Differences

Miner has greatly summarized it

 

[Yew Jin]

Re: Process FMEA vs. Equipment FMEA Differences

Thanks to all of you guys.

I believed the concept over here on the process and equipment FMEA is difference.

Management is looking on the machine FMEA which screen all the functionality on an auto machine such as loading function, XY movement, dispenser function, unloading function.

Such as the function do we consider the process?
I am confuse on the function and process for an auto machine for process which replace the manual process.

Can you guys provide me any FMEA for the machinery?

If we design a auto machinery to replace the manual process, should we do the process or machinery FMEA or both?

 

[Stijloor]

Re: Process FMEA vs. Equipment FMEA Differences

Thanks to all of you guys.

I believed the concept over here on the process and equipment FMEA is difference.

Management is looking on the machine FMEA which screen all the functionality on an auto machine such as loading function, XY movement, dispenser function, unloading function.

Such as the function do we consider the process?
I am confuse on the function and process for an auto machine for process which replace the manual process.

Can you guys provide me any FMEA for the machinery?

If we design a auto machinery to replace the manual process, should we do the process or machinery FMEA or both?

Hello Yew Jin,

I am a little bit confused about what you're looking for.....

I decided to do a search. Here are the results. Is there anything that would help answering your questions?

Stijloor.

 

[Yew Jin]

Actually I am confuse by the management concept.

Correct me if I am wrong.

Machinery FMEA objective is to evalaute the risk of the machinery part and tools that will be replace or wear and tear. To fond which item to be the first priority to prevent.

Process FMEA objective is to evaluate the risk of the special cause in the process which will affect customer inculding internal and external product characteristic requirement.