Dear forum members,
On what basis acceptance criteria can be decided for various instruments like vacuum gauge, pressure gauge, temperature sensor, temp. Indicator etc…
kindly suggest me…
regards
SVR
One word: RISK!
If there’s absolutely no risk to product then controls are minimal.
If there’s risk but downstream inspection / assessment mitigates the risk of releasing bad product then controls need to be increased to minimize scrap.
If there’s risk that lack of control of a system would cause bad product to be released, controls need to be very tight.
You need to do the analysis (pFMEAs, etc.) to determine what can happen if the instruments fail. Based on that you should be able to identify the level of control required for each.
[quote=yodon]One word: RISK!
If there’s absolutely no risk to product then controls are minimal.
If there’s risk but downstream inspection / assessment mitigates the risk of releasing bad product then controls need to be increased to minimize scrap.
If there’s risk that lack of control of a system would cause bad product to be released, controls need to be very tight.
You need to do the analysis (pFMEAs, etc.) to determine what can happen if the instruments fail. Based on that you should be able to identify the level of control required for each.[/quote]
Dear Sir,
Could you please elaborate pFMEAs
regards
svr
Sure. pFMEA is a “Process Failure Modes and Effects Analysis.” You look at your processes to determine how a flaw could be introduced. For example, if your process fails to maintain vacuum in tolerance, what is the effect on the product?
You may also want to consider Fault Tree Analysis (FTA). That takes a bottom-up look at the ways things could fail. For example, if you consider loss of vacuum tolerance, faults may include things like leaking lines, etc.
Step 1 :Review the process—Use a process flowchart to identify each process component.
Step 2 :Brainstorm potential failure modes—Review existing documentation and data for clues.
Step 3: List potential effects of failure—There may be more than one for each failure.
Step 4:Assign Severity rankings—Based on the severity of the consequences of failure.
Step 5:Assign Occurrence rankings—Based on how frequently the cause of the failure is likely to occur.
Step 6:Assign Detection rankings—Based on the chances the failure will be detected prior to the customer finding it.
Step 7:Calculate the RPN—Severity X Occurrence X Detection.
Step 8: Develop the action plan—Define who will do what by when.
Step 9:Take action—Implement the improvements identified by your PFMEA team.
Step 10:Calculate the resulting RPN—Re-evaluate each of the potential failures once improvements have been made and determine the impact of the improvements
[quote=DURGA PRASAD]Step 1 :Review the process—Use a process flowchart to identify each process component.
Step 2 :Brainstorm potential failure modes—Review existing documentation and data for clues.
Step 3: List potential effects of failure—There may be more than one for each failure.
Step 4:Assign Severity rankings—Based on the severity of the consequences of failure.
Step 5:Assign Occurrence rankings—Based on how frequently the cause of the failure is likely to occur.
Step 6:Assign Detection rankings—Based on the chances the failure will be detected prior to the customer finding it.
Step 7:Calculate the RPN—Severity X Occurrence X Detection.
Step 8: Develop the action plan—Define who will do what by when.
Step 9:Take action—Implement the improvements identified by your PFMEA team.
Step 10:Calculate the resulting RPN—Re-evaluate each of the potential failures once improvements have been made and determine the impact of the improvements[/quote]
sir,
i am know what is FMEA but i didnt have an exposure
so ,can u explain me pls giving an example
sarada