Debit Note
Meaning ~ A formal trade document issued by a buyer to decrease the amount payable to a seller, governing recoveries for shortages, pricing errors, or defect costs.
Rework Math
Meaning
Calculations used to determine the financial viability and labor requirements of fixing defective products provide the data needed to decide between salvage and disposal. This analysis compares the cost of the materials and the labor needed for the repair against the expected resale value of the corrected goods. It governs the decision making process after a quality failure and determines the most efficient path for recovering as much value as possible.
The use of the formula stops once the decision to either repair or scrap the items has been made and approved.
Labor Allocation
Estimating the amount of human effort required to fix a batch of goods is the most complex part of the calculation. The rework math must account for the hourly wage of the workers, the time taken for each unit, and the overhead costs of the facility where the work will be done. If the repair requires highly skilled technicians or expensive specialized equipment, the cost can quickly exceed the original manufacturing price of the product.
The process involves conducting a time study on a small sample of the defective items to get an accurate average for the whole lot. This data allows the manager to determine if the existing staff can handle the work or if a third party service provider is needed. If the labor cost is too high, the most logical decision is to discard the goods and start over.
Material Efficiency
Tracking the additional parts and consumables needed to bring the products back to standard is another critical component of the analysis. Sometimes a repair only requires a simple adjustment, but in other cases, it might involve replacing expensive components that were damaged during the first production run. The rework math includes the cost of these new parts and the cost of disposing of the old ones.
It also considers the risk that the repair process itself might damage more units, leading to a lower final yield. By looking at the total material balance, the company can see if the salvage operation is truly adding value or if it is just throwing good money after bad. This information helps in negotiating with the original supplier for the cost of the replacement parts.
Financial Feasibility
Determining the break even point for the recovery project provides the final answer to whether the work should proceed. The organization calculates the net recovery value by subtracting the total rework costs from the price they expect to get for the finished items. When this number is positive and high enough to justify the risk, the project is approved.
If the net recovery is negative or very small, the items are typically recycled or sent to a landfill. The cost of a bad decision in this area is a double loss for the firm, as they lose the original investment and the cost of the failed repair. This analysis is also useful for identifying which types of defects are worth fixing and which should be prevented at all costs.
The final report provides a lessons learned document that can be used to improve the primary manufacturing process and avoid future quality failures.