First Time Yield (FTY) is a traditional metric that tells you how many defects your process produces for before any improvement is done. Generally this measurement is used in the manufacturing or production field, but it can make the switch to your office easily. The formula for FTY is:
FTY: Total Unit Passed/Total Units Tested
So if you work at a membership organization and you processed 120 retirement requests and found that 50 requests were entered incorrectly, our FTY is .58 %. 70 is the total number of request entered correct or passed and the total number of units tested is 120 retirement requests.
If your process has multiple measurement areas, you will need to perform a FTY for every measureable step in the process. The great about FTY is that it is one of the simplest metrics in 6Sigma and it creates a create illustration of the current state of your process
What does it look like?
A FTY can look like any typical graph you have seen, but most will resemble the chart below. My fancier ones include the curve illustration for clients that highlight the cost of these errors to the client and how the improvements will be quantified.
What doesn’t FTY do?
FTY is a great place to start, but it is important to understand its limitations. FTY will not measure rework or provide any accounting for the cost in time or resources for that rework. There is a more accurate method for measuring that, Rolled Throughput Yield, which we will cover next week.
FTY is a great foundational measurement piece and a great way to introduce your company to 6Sigma, in a way that makes a lot of sense to the people doing the work.
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.