# Reducing gaging frequency/High Cpk

D

#### Dura_guy

I have a few processes that are extremely capable (> 7.0 Cpk). In QS-9000 4.9.2, reference is made to revising the control plan when a high degree of capability is demonstrated. Is there any guidelines as to how this can be accomplished, (other that atmospheric analysis?)

Currently we are gaging for these characteristics at a frequency of 3 pcs. per hour of production. Is there a formula I can apply that can help me determine if I can reduce the frequency of checks to every 2,3,4....etc. hours?

Thanks for your help!

Dura guy

N

#### noboxwine

Almost Miller Time

7.0 Cpk ! Wow ! I am sure that there is some esoteric, mathematical formula that can be used as a guideline for adjusting your frequency. But, here's what I have done in similar situations. First, is your process in CONTROL? I can show you a high Cpk all day long, but if the process is not in statistical control, then you can't predict it. If it is, I would simply use common sense (sorry, I tend to throw that in and confuse a lot of people) and change your freqeuncy to, say, every 1.5 hrs and monitor accordingly. If it's still good, 2 hrs. Simply let the data tell you how your process is behaving and reduce needless inspection accordingly. I am sure you'll find it pretty simple and effective. Rot's of ruck and have a nice day.
:thedeal:

#### Mike S.

##### Happy to be Alive
Trusted Information Resource
I agree with Noboxwine, but if you want a non-esoteric mathematical formula, one "guideline" I've used is 6 measurements between adjustments to the process. This won't work everywhere, but try noboxwine's idea and see if it would jive at all with mine.

Let us know how it works out. Maybe we'll all learn somethin'

D

#### D.Scott

I am certainly in agreement with the comments so far but remember that a change in the control plan should be run past the customer. Also, if you just open up your intervals, you stand the chance of going past the optimum before you realize it.

Why not take the control chart you currently have and do run studies based on that data. Calculate using every other entry for 2 hours, every 3rd for 3 hour etc. This will show what the capability will look like at those intervals. Include the studies with an analysis of the data and present the facts to the customer telling him you intend to change the intervals on the control plan.

When he agrees, make your change. This way, the data is still there and current in case you run into a problem. It is also less confusing to the employees who are collecting the data.

Dave

#### Mike S.

##### Happy to be Alive
Trusted Information Resource
Great idea.

Sage advice. Wish I'da said it first.

And Energy said common sense was dead! Not completely it ain't!

Thread starter Similar threads Forum Replies Date
Reducing CE marking cost using manufacturer test reports CE Marking (Conformité Européene) / CB Scheme 5
D Strategies for reducing software documentation burden IEC 62304 - Medical Device Software Life Cycle Processes 10
M Methods of reducing/eliminating the systematic component of error General Measurement Device and Calibration Topics 0
PFMEA - Reducing Severity (S) Ranking - Manufacturing Process Design Changes FMEA and Control Plans 4
B Reducing variation through multiple readings Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 6
M Reducing Cost of Poor Quality - Your opinion requested Quality Manager and Management Related Issues 14
B EMC Repeat Justification - Reducing NRTL testing required after modification of ME IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
Reducing cost of IEC 60601 3rd edition testing IEC 60601 - Medical Electrical Equipment Safety Standards Series 14
Reducing Variation via Multiple Readings Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 5
9 Ideas for reducing Human Error during Order Receipt Quality Manager and Management Related Issues 4
D Reducing Within Part Variation during a Gage R&R Study Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 26
O Reducing a Cpk which is higher than 1.33 Capability, Accuracy and Stability - Processes, Machines, etc. 12
Q Reducing the Frequency of Audits - Internal Audit Programme 2012 Internal Auditing 13
T Reducing End of the Line Skipped Rabbit Testing Reliability Analysis - Predictions, Testing and Standards 3
S SMED on Punching Machine - Reducing Set-Up Time Lean in Manufacturing and Service Industries 4
Q Reducing the Frequency of a Production Line Test Inspection, Prints (Drawings), Testing, Sampling and Related Topics 14
M What is your most significant experience in Reducing Injection Moulding Cycle Time? Manufacturing and Related Processes 18
P ROI (Return on Investment) for Reducing Order to Fullfillment Lead Time Manufacturing and Related Processes 1
A Operation Control for Reducing Electricity Consumption Miscellaneous Environmental Standards and EMS Related Discussions 18
W Reducing Documentation for In-Process Inspections ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 4
C Reducing Material Handling Costs - In-Floor Tow-Line Conveyor System Lean in Manufacturing and Service Industries 7
R Chain Sampling Plan explanation and help - Reducing sample sizes (compared to Z1.4) Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
C Reducing paperwork and placing in Systems electronically - Electronic documents ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
N Reducing Equipment Variation - Appraisal Variation - Newly developed product Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 1
J Reducing Engineering Change Orders Document Control Systems, Procedures, Forms and Templates 16
P Traffic, Distribution, Imports - Reducing Cost, Traffic Process Manufacturing and Related Processes 28
J Reducing Inspection Costs - Sampling Plans and Producer's Risk Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
T One Work Instruction instead of Many - Reducing Documentation Document Control Systems, Procedures, Forms and Templates 7
V Six Sigma Project on Reducing Plastic Injection Molding Rejects Six Sigma 10
K RPN reduction - Occurrance Reduction - Reducing occurance of defect on line FMEA and Control Plans 1
C Reducing Variation through Multiple Readings - MSA 3rd edition Chapter 5d Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 8
S Environmental Management Program - Reducing electric and fuel use, waste management Miscellaneous Environmental Standards and EMS Related Discussions 25
A Reducing The Amount Of Time Spent While Improving The Effectiveness Of Meetings QS-9000 - American Automotive Manufacturers Standard 4
M Reducing both Detection and Occurance in a Design FMEA WITHOUT a Design Change FMEA and Control Plans 8
D Reducing the Number of SPC Charts used: We have many highly capable processes Statistical Analysis Tools, Techniques and SPC 6
S Strategies for reducing Sampling on incoming bulk material - low volume, ingots Inspection, Prints (Drawings), Testing, Sampling and Related Topics 2
D Traceability - Reducing final inspections on separate lots QS-9000 - American Automotive Manufacturers Standard 3
D Corrective Action Process Review - Reducing the scope of our NRS Nonconformance and Corrective Action 6
Cost effective thread gaging with ISO 9001 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 2
MSA for gaging which specifies process parameters and 7.6.1 Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 4
E Floor Gaging for Internal Thread Major Diameters Inspection, Prints (Drawings), Testing, Sampling and Related Topics 6
F Optical Gaging Systems - Shadows, debris, etc. cause parts to measure out of spec Measurement Uncertainty (MU) 7
E SAE-AS8879 Threaded Hole Gaging - .4375UNF-3B and .4375-UNJF-3B Inspection, Prints (Drawings), Testing, Sampling and Related Topics 15
P Doubt about MSA for Attributes Gaging - Reference Value Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 8
Thread Gaging: Hand Tight Definition Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1
Part Tolerance and TAR (Test Accuracy Ratio) - Non-Fixed Gaging General Measurement Device and Calibration Topics 2
S Laser Gaging System Gage R&R Gage R&R (GR&R) and MSA (Measurement Systems Analysis) 9
R Thread Inspection - Using go/no-go gaging to inspect threads Inspection, Prints (Drawings), Testing, Sampling and Related Topics 9
J "Gaging" the performance of a replacement gauge Capability, Accuracy and Stability - Processes, Machines, etc. 6
In need of good Gaging house in the Midwest Inspection, Prints (Drawings), Testing, Sampling and Related Topics 1