Meaning
Percentage of units that fail to meet quality standards during the fabrication or assembly process and are subsequently scrapped or sent for rework. High manufacturing yield loss indicates inefficiency in the assembly process or defects in the raw materials used to build the product. This metric is expressed as the difference between the total number of units started and the total number of units passed.
Defect Classification
Failures are categorized by the stage where they occur, such as component placement or final functional test. While tracking manufacturing yield loss, engineers distinguish between units that are permanently scrapped and those that can be repaired. This distinction helps in calculating the true cost of production.
Process Impact
High failure rates at a specific station suggest a problem with the machinery or the training of the operator. Reducing manufacturing yield loss involves adjusting the oven profiles or the pressure of the placement heads to ensure better solder joints. Small improvements in these areas lead to a measurable increase in the total factory output and a reduction in the time spent on manual rework.
Analyzing the failure logs from the automated test equipment provides the specific location of the most frequent defects.
Financial Boundary
Estimates of product cost depend on an accurate prediction of the expected pass rate. When the manufacturing yield loss exceeds the planned budget, the profit margin for the entire project is reduced.
