Six Sigma is often thought of as a statistic heavy method and to some degree that is true. But the truth about statistics is if you don’t understand what they are trying to tell you, then they are just numbers on a page. The good news is that the purpose of Six Sigma metrics generally fall into 3 categories: can I make it better, can I make it faster or can I make it cheaper.
Basic Metrics Help Me Make It Better
These metrics are typically Defects per Unit (DPU), Defects per Million Opportunities (DPMO) and Rolled Throughput Yield (RTY). The purpose of these metrics is to decide whether you can eliminate waste and increase the quality of your end product. This is a metric that will not create an almost answer, you will identify and work from a root cause perspective.
Basic Metrics Help Me Make it Faster
This measurement deals almost exclusively with cycle time, this category is almost singularly concerned with reducing production and delivery time. Focus on the cycle time requires you to focus on the process from cradle to grave. You are looking very much to reduce variations and eliminate non value added activities.
Basic Metrics Help Me Lower Cost
This metric requires you to deal with the cost of poor quality (COPD). If this is a measurement that you are using, your purpose is to find out where the quality problem is, how much it is costing the organization and how to eliminate it.
This is a basic summation of how you will decide what type of metrics to use, next week we will go into detail about specific metrics. Knowing why you are measuring something and what you need those measurements to tell you is the most important part of your 6Sigma project. Your belt will be able to walk you through a specific measurement and offer advice as to whether or not it is the best metric to use.