Manufacturing Yield
What is manufacturing yield?
Manufacturing yield, also called production yield, is the metric that measures the probability of getting good products from manufacturing processes. Calculating manufacturing yield is important if you aim to follow the principles of lean manufacturing production.
There are several types of manufacturing yield, including overall manufacturing yield/output, first-time yield, and rolling throughput yield, which each will be discussed below.
What is overall manufacturing yield?
Overall manufacturing yield is a percentage calculated as such:
Overall manufacturing yield % = (Good parts produced / Total number of parts started in production) x 100
For example, if you manufactured 10,000 reams of paper and 9,000 of them were good, your overall manufacturing yield would be 90%.
The issue with overall manufacturing yield is that it doesn’t always tell the entire story. If your process involves reworking or re-testing defective products so that they will be good, this is not reflected in your overall manufacturing yield. That’s where first-time yield comes in.
What is first-time yield (FTY)?
First-time yield measures the number of good products produced that make it through the entire manufacturing process without failures. In order to calculate FTY, you must break your process down into steps, identifying each stage in the process where a product can be passed or failed.
For each of these stages, you calculate FTY as such:
First-time yield % = (Parts passed with no failures / Total number of parts produced)
FTY is calculated independently for each manufacturing stage, counting only the number of parts that passed their first time at the given stage.
What is rolling throughput yield?
Throughput yield, also called rolling throughput yield (RTY) is calculated by multiplying together the FTYs of each production stage. This number offers an accurate indicator of overall yield taking reworking and re-testing into account.
How calculating manufacturing yield benefits process manufacturing plants
For process manufacturing plants, each rework and retest comes with a cost, including wasted materials, wasted time, and wasted money. Plants that only look at overall yield may receive a false picture of efficiency.
By calculating FTY and RTY, process manufacturers get a more accurate sense of their plants’ efficiency, and are able to identify which manufacturing stages in particular may be costing the most time and money on reworks. This data is crucial for optimizing productivity with continuous improvement. By tracking FTY and RTY accurately and using data-based insights wisely, process manufacturers can boost revenue while cutting down on costs.