First harvest

The Erstausbeute (English first pass yield , abbreviated FPY ) is a measure of the quality assurance and quality management . The initial yield describes the proportion of components or assemblies that are free of defects after the first production run - i.e. without repair steps. It therefore corresponds to the yield in semiconductor production .

The first yield (FPY) can be given as a dimensionless percentage - the percentage sign is often left out in careless notation - or in millionths . An initial yield of 86 (more precisely: 86%) means that 86 out of 100 units meet the requirements. The higher the initial yield, the higher the profitability from a qualitative point of view.

Chained production process

If a production process consists of several steps, the initial yield for the entire manufacturing process (the total yield) is calculated as the product of the individual yields.

Example: A production process for 100 pieces consists of four consecutive work steps (AG 1, AG 2, AG 3, AG 4). In order to determine the initial yield (FPY) for this, the initial yields of the individual operations must be determined and multiplied:

• AG 1: Out of 100 pieces, 10 pieces fail, you get 90 good pieces. FPY = 90/100 = 0.90
• AG 2: Out of 90 pieces 10 pieces fail, you get 80 good pieces. FPY = 80/90 = 0.89
• AG 3: Out of 80 pieces, 5 pieces fail, you get 75 good pieces. FPY = 75/80 = 0.94
• AG 4: 5 of 75 pieces fail, you get 70 good pieces. FPY = 70/75 = 0.93

The FPY for the entire process is then calculated as follows:

${\displaystyle {\mbox{FPY}}_{AG1}\cdot {\mbox{FPY}}_{AG2}\cdot {\mbox{FPY}}_{AG3}\cdot {\mbox{FPY}}_{AG4}=0{,}90\cdot 0{,}89\cdot 0{,}94\cdot 0{,}93=0{,}70}$

Out of 100 pieces, 70 pieces emerged as good parts - OK (OK) - in the first process run without rework .

Individual evidence

1. ↑ Günter Hofbauer, Anita Sangl: Professional product management: The process-oriented approach, framework conditions and strategies . 2nd Edition. John Wiley & Sons, 2011. Here p. 189.