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Jidoka maisake proofing tool Poka Yoke.pptx
- 1. JIDOKA & MISTAKE PROOFING For BhagyalaxmiRolling Mills
- 2. JIDOKA & MISTAKEPROOFING
- 3. Purpose •To understand thefundamental concepts of Jidoka and Mistake Proofing •To generate and apply mistake proofing ideas for OE Defects
- 4. Contents •Basic concepts ofJidoka •Mistake Proofing • Concepts • Examples •Exercise •Sharing of OE Problems with Root cause and Poka Yoke Ideas
- 5. Jidoka- The flowfacilitator • Jidoka means is "autonomation" or "automation with a human touch." • Example of a machine that will detect a problem and stop production automatically rather than continue to run and produce bad output. • The principle's origin goes back to 1902 when Sakichi Toyoda invented a simple but ingenious mechanism that detected a broken thread and shut off an automatic loom. That invention allowed one operator to oversee the operation of up to a dozen looms while maintaining perfect quality. • The jidoka pillar is often labeled "stop and respond to every abnormality."
- 6. Principles of Jidoka…(I) 1. Prevention – Mistake Proofing engineers the product or process so that it is impossible to make a mistake at all. Examples : Limit switches to assure a part correctly placed or fixtured before process is performed; part features that only allow assembly the correct way, unique connectors to avoid misconnecting wire harnesses or cables, part symmetry that avoids incorrect insertion. 2.Facilitation- – Visual Control employs techniques and combining steps to make work easier to perform. Examples: visual controls including color coding, marking or labeling parts to facilitate correct assembly; exaggerated asymmetry to facilitate correct orientation of parts; a staging tray that provides a visual control that all parts were assembled, locating features on parts. 3.Detection- Andon involves identifying an error before further processing occurs so that the user can quickly correct the problem. Examples : sensors in the production process to identify when parts are incorrectly assembled, built-in self-test (BIST) capabilities in products.
- 7. Principles of Jidoka…(II) 4.Mitigation seeks to minimize the effects of errors. Example: Fuses to prevent overloading circuits resulting from shorts; products designed with low-cost, simple rework procedures when an error is discovered; extra design margin or redundancy in products to compensate for the effects of errors. 5.Elimination seeks to eliminate the possibility of error by redesigning the product or process so that the task or part is no longer necessary. Example: Product simplification or part consolidation that avoids a part defect or assembly error in the first place. 6.Replacement substitutes a more reliable process to improve consistency. Examples: Use of robotics or automation that prevents a manual assembly error, automatic dispensers or applicators to insure the correct amount of a material such as an adhesive is applied.
- 8. Contents •Basic concepts ofJidoka •Mistake Proofing • Concepts • Examples •Exercise •Sharing of OE Problems with Root cause and Poka Yoke Ideas
- 9. Definition Mistake •The execution ofa prohibited action, the failure to correctly perform a required action or the misinterpretation of information essential to the correct execution of an action Mistake proofing •The use of process or design features to prevent manufacture of non-conforming product. •It is popularly known as Poka Yoke
- 10. Mistake Proofing (PokaYoke):- A technique to prevent mistakes • Poka-yoke was coined in Japan during the 1960s by Shigeo Shingo who was one of the industrial engineers at Toyota. • Poka-yoke refers to techniques that make it impossible to make mistakes. • Poka-yoke is used wherever something can go wrong or an error can be made Poka-yoke ensures that proper conditions exist before actually executing a process step, preventing defects from occurrence • Poka-yoke does not need to be costly. • Where prevention is not possible, poka-yokes perform a detective function, eliminating defects in the process as early as possible Make it Impossible to do Things Wrong Make it Impossible to do Things Wrong Make it Impossible to do Things Wrong Make it Impossible to do Things Wrong Make it Easy to Do Things Right Make it Easy to Do Things Right …… and Difficult to Do Things Wrong …… and Difficult to Do Things Wrong Make it Easy to Do Things Right Make it Easy to Do Things Right …… and Difficult to Do Things Wrong …… and Difficult to Do Things Wrong
- 11. Types of Errorsthat create product defects • Processing error: • Process operation missed or not performed per the standard operating procedure. • Setup error: • Using the wrong tooling or setting machine adjustments incorrectly. • Missing part: • Not all parts included in the assembly, welding, or other processes. • Improper part/item: • Wrong part used in the process. • Operations error • Carrying out an operation incorrectly; having the incorrect version of the specification. • Measurement error: • Errors in machine adjustment, test measurement or dimensions of a part coming in from a supplier.
- 12. Step by StepApproach in applying Poka Yoke for a defect Identify the Operation/Process where defect occurs Identify root cause for the defect using 5- why Decide the right Poka Yoke Approach 1. Shut down type (Preventing an error being made) 2. Attention type (Highlighting that an error has been made) Determine the type of Poka Yoke device 1. Contact - Use of shape, size or other physical attributes for detection 2. Constant number - Error triggered if a certain number of actions are not made 3. Sequence method - use of a checklist to ensure completing all process steps is appropriate Implement the method for results
- 13. Choosing the righttype of mistake proofing Contact - Use of shape, size or other physical attributes for detection • Errors can be prevented by changing the shape of the part or the fixture. • A sensor can be installed to ensure that an assembly process won’t begin until the correct part has been installed in the correct position. Constant number - Error triggered if a certain number of actions are not made • Parts kit. All the parts required for an assembly are loaded into the kit, which is typically a thermoformed plastic tray. Cavities in the tray are designed to match the shape or number of parts in the assembly. Thus, before assembly, the operator knows if any parts are missing. And, if any parts are left over in the tray after assembly, the operator instantly knows that a mistake has been made. • A limit switch can be used to make certain that the correct number of assembly steps has been performed Sequence method - Use of a checklist to ensure completing all process steps is appropriate
- 14. Common Mistake-proofing Devices •GuidePins •Blinking lights and alarms •Limit switches •Proximity switches •Counters •Checklists
- 15. Poka Yoke- Example1: Similar Gears • An electrical products company made a timer switch that was equipped with a frequency selection mechanism so it could be used in areas with either 50- or 60-hertz power. • The 50- and 60-hertz gears were installed next to each other on the same shaft. The only difference between the two gears was three teeth, making it difficult to tell the gears apart with the naked eye. And because the gears fit interchangeably on the shaft, assembly errors were common. • Poka Yoke1: Engineers modified the holes in the gears and the shape of the shaft to that the gears could only fit on the shaft one way. • Poka Yoke 2: In addition, the 50-hertz gear was molded in white plastic, and the 60-hertz gear was molded in blue plastic, so they could be identified at a glance. • Installation errors were eliminated at no increase in product cost.
- 16. Poka Yoke- Example2: Ambiguous Information
- 17. Poka Yoke- Example3: Missing Parts/Incomplete Assembly
- 18. Poka Yoke- Example4: Missing Operation
- 19. Poka Yoke- Example5: Missing Operation Light Sensor to flush water The two pins in the marked area switch off the dryer even if it is kept on.
- 20. Poka Yoke- Example6: Missing Operation Keys to initiate power connection in Hotel rooms Limit switch to avoid coffee spillage Sensor to fill water in a Swimming pool
- 21. Poka Yoke- Example7: Wrong Fittings
- 22. Poka Yoke- Example8: Wrong Fittings
- 23. Poka Yoke- Example9: Missing Parts after usage
- 24. Poka Yoke- Example10: Wrong Operation Overflow Hole Overflow hole in a wash basin If you open one pull out , the others will not open
- 25. Poka Yoke- Example11: Unsafe Operation Trolley will not move if the yellow handle is not pushed- Avoids trolley movement with luggage Dryer stops if lid is open Limit switch for safety- Motor will not start if lid is not closed
- 26. Poka Yoke- Example12: Easier Detection/Facilitation Indicator turns HOT from black if heated up One can’t open the door without removing the coat
- 27. Poka Yoke: Examples13: Easy Detection/Facilitation
- 28. Contents • Basic conceptsof Jidoka • Mistake Proofing • Concepts • Examples • Exercise • Sharing of OE Problems with Root cause and Poka Yoke Ideas
- 29. Exercise: Select 2OE defects from the list below, analyze the problem for root cause and evolve suitable Poka Yoke Ideas • Dipstick Wrong Fitment • OPG Adoptor loose • Thermostat Stud Missing • Feedpump Adoptor Loose • Flywheel depth minus • Thread missing in Flywheel • Starter mounting hole undersize • Tacho drive pin less • Belt not answering in groove • Sump to housing mounting hole off • Sump Mismatch • Block drain plug missing • EMF Position wrong
- 30. July 16, 2025arvind consulting group 30
- 31. July 16, 2025arvind consulting group 31
Editor's Notes
- #9 (READ SLIDE TEXT) A caveat about this definition: We do not use errors and mistakes as synonyms. However, in this presentation we draw on the work of many people, and some authors will use the word mistake as a synonym with error. Where one of these is quoted, we have not changed their words. We do indicate their less precise use of the word mistake by italicizing it on the slide.