Calculate monthly reject rate, rejected quantity, rejection losses and the financial impact of metal production defects.
Metal reject rate is the percentage of manufactured units that are rejected because they fail to meet the required specification or acceptance criteria.
A reject rate can be tracked by month, production line, machine, product family, material or individual process. Converting the percentage into a financial value makes the effect of quality losses easier to understand.
The calculator first estimates the number of rejected parts from monthly production and the entered reject rate.
The gross rejection cost is then estimated using the cost assigned to each rejected part. Recovery value is deducted from the gross loss, while the reworkable portion is modeled separately.
A small percentage of rejected parts can represent a substantial monthly loss when production volume is high. The financial impact can include material already consumed, processing time, machine capacity, labor and inspection resources.
Rejected parts do not always become scrap. Some nonconforming parts may be recoverable through rework, while others may have residual material value through recycling or resale.
Rejected metal may retain value because the material can sometimes be recycled. The recovery value entered into this calculator reduces the estimated net rejection loss.
Actual scrap recovery prices depend on alloy, contamination, form, quantity, market conditions and the terms offered by the recycling or scrap buyer.
Some rejected parts can be corrected rather than scrapped. Entering a reworkable percentage allows the calculator to separate the estimated rework portion from the remaining rejected or scrap quantity.
The rework cost is then estimated separately so that the total financial impact is not treated as identical to a complete scrap loss.
Suppose a production operation makes 10,000 parts per month and has a 2% reject rate. The estimated rejected quantity is:
If each rejected part represents a $25 production cost, the gross rejected-part value would be $5,000 before considering recovery and rework.
This demonstrates why monitoring both reject percentage and production volume is important. A constant reject percentage can still create a larger financial loss when production volume increases.
Reject rate and rejection cost measure different aspects of production quality.
A process with a 1% reject rate can be more expensive than a process with a 5% reject rate if the first process produces much higher-value components.
The calculator provides both the estimated monthly net rejection loss and a projection over the number of months entered.
The projection assumes the entered production volume, reject rate and cost structure remain constant. Actual production conditions can vary.
Financial rejection data can help prioritize improvement projects. A defect with a low frequency but very high cost may deserve attention before a frequent defect with minimal financial impact.
Combining reject quantity, defect frequency, cost per part and rework potential gives a more useful picture of production quality performance.
This calculator provides an estimate based on the production and cost assumptions entered. It does not automatically account for lost production capacity, customer penalties, delivery delays, warranty claims, administrative costs or opportunity costs.
The definition of a reject can also vary between manufacturing quality systems. For formal reporting, use the definitions and accounting rules applicable to your operation.
What is reject rate?
Reject rate is the percentage of production units that are rejected because they fail the required acceptance criteria.
How are monthly rejected parts calculated?
Monthly production is multiplied by the reject rate expressed as a decimal.
Can this calculate monthly scrap losses?
Yes. It estimates rejected quantity and financial loss using the cost and recovery values entered.
Does reject rate include rework?
That depends on the quality reporting definition used by the manufacturing operation. The calculator separately models a reworkable portion.
Why is recovery value deducted?
Recoverable metal has residual value, so it reduces the estimated net financial loss.
Can I project annual losses?
Yes. Enter 12 months to estimate a simple annual projection based on the entered monthly conditions.