STM Quality Limited PokaYoke TOTAL QUALITY MANAGEMENT PokaYoke

STM Quality Limited Poka-Yoke TOTAL QUALITY MANAGEMENT Poka-Yoke ©©ABSL Power Solutions STM Quality Limited 2007

What is Poka-Yoke? STM Quality Limited l This is known as ‘MISTAKE-PROOFING’ l From Japanese: l Yokeru (avoid) l Poka (inadvertent errors) © STM Quality Limited

What Does Poka-Yoke Do? STM Quality Limited l Eliminates the cause of an error at the source; l Detects an error as it is being made; l Detects an error soon after it has been made but before it reaches the next operation. © STM Quality Limited

Are Errors Unavoidable? STM Quality Limited l There are two approaches to dealing with errors: l 1. ERRORS ARE INEVITABLE! l 2. ERRORS CAN BE ELIMINATED! © STM Quality Limited

1. Errors Are Inevitable STM Quality Limited l People always make mistakes. l While we accept the mistakes as natural, we blame the people who make them. l With this attitude, we are likely to overlook defects as they occur in production. l They may be detected at final inspection, or worse still, by the customer. © STM Quality Limited

2. Errors Can Be Eliminated STM Quality Limited l Any kind of mistake people make can be reduced or even eliminated. l People make fewer mistakes if they are supported by proper training and by a production system based on the principle that errors can be avoided. © STM Quality Limited

Inspection STM Quality Limited l One method of detecting errors is inspection. l There are two major types of inspection. l 1. SAMPLING INSPECTION. l 2. 100% INSPECTION. © STM Quality Limited

Sampling Inspection STM Quality Limited l In some factories, the attitude is: l “It may take all day to inspect all product”. l “There may be a few defects, but sampling is the most practical way to check”. © STM Quality Limited

Sampling Inspection - Reflection STM Quality Limited l Think about sampling. l With sampling, there is a chance that an error may go undetected. l Even if 1 part in 1000 is defective, the customer who buys that part has a 100% defective product! © STM Quality Limited

Sampling Inspection - Reflection STM Quality Limited SAMPLING INSPECTION MAKES SENSE ONLY FROM THE MANUFACTURER’S VIEW, NOT FROM THE CUSTOMER’S! © STM Quality Limited

2. 100% Inspection STM Quality Limited l In the best factories, the attitude is: l “We won’t tolerate a single defect!” l “We will organize production so that 100% of the product can be easily inspected”. l “That makes the most sense”. © STM Quality Limited

100% Inspection - Reflection STM Quality Limited l Think about 100% inspection. l Even one defective product is enough to destroy a customer’s confidence in a company. l To stay competitive a company must supply good product in thousands. l The best way to achieve this is to organize production to inspect 100% of the products. © STM Quality Limited

The User Is The Best Inspector STM Quality Limited l No one intends to make mistakes. l While we are working, errors can show up without us noticing. l How can we catch these errors before they turn into defective products? © STM Quality Limited

Finding Defects in the Subsequent Process STM Quality Limited l We don’t expect to find defects, but if a product we use doesn’t do what it is supposed to do, then we know it is defective. l Users are the best at discovering defects! © STM Quality Limited

Finding Defects in the Subsequent Process STM Quality Limited l Since subsequent processes are also ‘users’ of the product being manufactured, they are also expert at finding defects. l If products are produced in a flow, each product is sent to the next process as soon as it is finished and defects are therefore found immediately. © STM Quality Limited

Two Strategies for Zero Defects STM Quality Limited l 1. DON’T MAKE IT! © STM Quality Limited

1. Don’t Make It! STM Quality Limited l Don’t make product you don’t need. l The more you make, the greater the opportunity for defects. l Follow ‘just-in-time’ principles by only making what is needed, when it is needed in the amount needed. © STM Quality Limited

Two Strategies for Zero Defects STM Quality Limited l 2. Build Safeguards © STM Quality Limited

2. Build Safeguards STM Quality Limited l The user is an expert in finding defects. l Therefore build safeguards into the production process. l Quality can be built into products by implementation of Poka-Yoke. © STM Quality Limited

Poka-Yoke Devices STM Quality Limited l Human errors are usually inadvertent. l Poka-yoke devices help us avoid defects, even when inadvertent errors are made. l Poka-yoke helps build quality into processes. © STM Quality Limited

Poka-Yoke Devices – Error Detection and Alarms STM Quality Limited © STM Quality Limited

Poka-Yoke Devices – Checklists STM Quality Limited © STM Quality Limited

Poka-Yoke Example STM Quality Limited l It is possible to mount the blank the wrong way onto the pierce tool. BLANK PIERCED BLANK INCORRECT l As the blank can fit the pierce tool in many ways, how can this be prevented? © STM Quality Limited

Poka-Yoke Example STM Quality Limited l By fitting a block into the pierce tooling, the blank plate can only go on one way. BLOCK © STM Quality Limited

Poka-Yoke STM Quality Limited POKA-YOKE MEANS ZERO DEFECTS © STM Quality Limited