Six-Sigma Quality The second “pillar” of the Toyota Production System is Jidoka A system for detecting defects and abnormal conditions in production Automatically stopping a line so that quality issues can be quickly addressed.

House of Toyota

Data Driven Approach In even the leanest manufacturing plants, some quality issues arise that are difficult to identify and correct Six Sigma is especially effective at identifying the root cause of quality problems – and eliminating defects by reducing variation in manufacturing processes

Variation - The Root Of All Process Evil As a customer, the worst experience I can imagine is being a casualty of process variation. 'It doesn't seem that bad,' you may be thinking to yourself. Just remember back to the last time you:

Remember When You: Went grocery shopping only to select the slowest teller in the store Received a haircut that was shorter or longer than usual, and definitely not what you asked for Decided to go shoe shopping, but got stuck with the most ignorant salesperson available

Consider the general concept of variation by examining the preparation time (in minutes) of 10 pizzas being prepared by your two local pie shops. The times are listed below ABC Pizzeria XYZ Pizza To Go

If we use common statistical tools, such as Mean, Mode and Midrange, we get the following results: ABC PizzeriaXYZ Pizza To Go Mean7.15 Mode7.7 Midrange7.1

From these results the two pizza parlors have the same measures of central tendency, so, on average, customers wait the same amount of time for pizzas at the two restaurants Based on these measurements alone, we cannot see any distinguishable difference between the two processes

Return to the original data points, There is a very distinguishable difference: ABC Pizza has preparation times with much less variation than the times for XYZ Pizza. ABC Pizzeria XYZ Pizza To Go

If all other characteristics of the pizza (taste, temperature, size, topping quality, service friendliness, etc.) are equal, customers are likely to prefer the ABC Pizza where they will not become annoyed by being the one person whose pizza preparation time is much slower than the others

Six Sigma at many organizations simply means a measure of quality that strives for near perfection Six Sigma is a disciplined, data-driven approach and methodology for eliminating defects Driving towards six standard deviations between the mean and the nearest specification limit in any process -- from manufacturing to transactional and from product to service

From a manufacturing standpoint, that means just 3.4 defects per million products or parts made Surprisingly, manufacturing 99% without defects means you’ll have 10,000 defects per million – and at 95% that number jumps to 50,000 defects.

The quality tools and techniques that were named “Six Sigma” in 1986 by Motorola (actually by a Motorola engineer named Bill Smith) are not new They were developed over the past 50 or more years, through the work of quality experts such as Deming, Juran and others.

The Journey

Data Driven Approach Despite the use of the term today, Six Sigma is actually a numerical measurement of quality To achieve Six Sigma, precisely % of what you do must be without defects

Key Concepts of Six Sigma Critical to Quality: Defect: Process Capability: Attributes most important to the customer Failing to deliver what the customer wants What your process can deliver

Key Concepts of Six Sigma Variation: Stable Operations: Design for Six Sigma: What the customer sees and feels Ensuring consistent, predictable processes to improve what the customer sees and feels Designing to meet customer needs and process capability

Deming & Juran “It is not necessary to change. Survival is not mandatory.” W. Edwards Deming "Without a standard there is no logical basis for making a decision or taking action." Joseph M. Juran