Where in the World are Poka-yoke? They exist in the world around us… (they’re out there)
Mistake-Proofing Devices On Your Car Can’t start the car unless it’s in park or clutched Can’t fit a diesel nozzle in the gas tank Doors lock when speed is greater than 5 miles per hour Bell chimes when headlights left on Headlights automatically burn & extinguish Bell chimes when seatbelt not worn Indicator lights when fuel is low Gas cap is attached to car by a lanyard Oil and fuel specs are listed on caps or tanks Bell chimes when turn signal left on Light indicates that parking brake is engaged
Where in the World are Poka-yoke? Let’s brainstorm!
Now, where have you seen one? Describe a “poka-yoke” you have experienced… (a mistake-proofing thingy) RULES – Everyone participates – No judgments or teasing – No body language – Play off each others ideas – Write so others can see – Promote a “Can do, won’t fail” attitude – Start with “Open” questions… “ What would we do to fix?” “What are some ways we could…” “If anything were possible, what…”
Top Causes of Errors Processing omissions: leaving out one or more process steps Processing errors: process operation not performed according to the standard Error in setting up: using wrong tooling or incorrect setting/ adjustment Missing parts: not all parts are included in assembly/ process Improper part/ item: wrong part installed in assembly
Top Causes of Errors Processing wrong work piece: wrong part machined/ processed Operations errors: incorrect revision or specification sheet Errors in equipment, maintenance or repair: Defects caused by incorrect repairs or component replacement Error in preparation of inspection equipment, fixtures or tools: Damaged inspection tooling; poorly designed fixtures or wrong tools; mis- measurement
Q) Why a Mistake-proof Hierarchy? 26 A) So you don’t have to “fix” the problem again! Full Automation Awareness Fail-Proof Simplification Training Behavior typically reverts back The process is changed to be less dependent upon people Most Desired Least Desired No Manual Intervention Impossible to Fail Eliminate Activity Certification and Audits Notification
Example Alert the operator at the point of mistake… Four xample, when one makes a misteak, an effective Poko-Yoke system will alert the operotor that a misteak was made, where it was made, and even how the misteak was made
Example IS GAS CAP SECURE? – Tighten till you hear the “click”
Example Computer Start-up Routines – [password/log-in/pin etc] Computer Shut-down Routines [series of low battery warnings/ actions taken]
What are the Conditions? (ripe for poka-yoke) 1.Adjustments 2.Unclear or no instructions 3.Undefined process 4.Many units/mixed units 5.Multiple steps 6.Infrequent production 7.Ineffective or lack of standards 8.Multiple handoffs 9.Hand processing 10.Rapid repetition 11.High volume demand or deadline pressures 12.Environmental conditions
Try It ! Mistake-Proof This: A local countertop company makes and then loads the countertop pieces on to a truck and goes to the customer’s home and installs the countertop. More than 15% of all installation jobs have to be done with more than one trip to the customer’s home because one or more pieces of the countertop was not loaded on the truck. Propose a change that will ensure all the material is loaded on the installation truck.
Try It ! Mistake-Proof This: The far-sighted instructor in a rush to get to work on time often forgot and left his glasses at home. Propose a change that will ensure the instructor does not forget his glasses.
Try It ! Mistake-Proof This: Mechanics in the instrument lab have to calibrate instruments in accordance with a procedure that has several steps. They sometimes inadvertently skip a step in the procedure. Propose a change that will ensure no steps are skipped.
Go Forth Identify what your impediments to improvement are Work on those and you will be on the right track In particular, what are barriers to – higher equipment uptime – higher process capability – safer environment or equipment – higher capital and labor productivity without adding cost or more highly trained personnel I call this building better process stability
Look for these Conditions: 1.Adjustments 2.Unclear or no instructions 3.Undefined process 4.Many units/mixed units 5.Multiple steps 6.Infrequent production 7.Ineffective or lack of standards 8.Multiple handoffs 9.Hand processing 10.Rapid repetition 11.High volume demand or deadline pressures 12.Environmental conditions Key Points about Mistake Proofing
What is Your Poka-Yoke? An idea you can put into practice… Process / Step: _________________________ Describe the Error: ______________________ Mistake-proofing Measure: _________________ _____________________________________ What foolish action does it prevent? ----------------------------------------------------
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