Cost of poor quality calculator

What it works out

The cost of poor quality calculator turns records from the business into a figure for this decision: all the money lost to quality in one number. Use it when the responsible quality inspector and production supervisor needs a consistent answer for this specific task. The answer uses only the values entered. Record the measurement period beside it.

What you need

Use the same item, period and measurement unit for related inputs. If a figure comes from an estimate rather than an actual record, mark it as estimated. Keep your original figures beside the result.

The formula

In plain words, calculate poor quality cost using the measured inputs below. The expressions are shown without hidden rounding so they can be checked by hand.

• poor quality cost: poor_quality_cost = scrap_cost+rework_cost+reinspection_cost+returns_cost+extra_freight+debit_notes+warranty_cost.

Formula basis from the supplied taxonomy: total = scrap + rework + re-inspection + customer returns + extra freight + debit notes + warranty costs. The calculation assumes the named inputs describe the same job and accounting period. Keep quantities, rates and measured units consistent.

A worked example

Illustrative example: a foundry uses the figures in the table above. These are example inputs, not industry averages. For this example, the main figures are scrap cost: ₹1,45,000, rework cost: ₹82,000, reinspection cost: ₹19,000, returns cost: ₹44,000.

1. Poor quality cost: scrap_cost+rework_cost+reinspection_cost+returns_cost+extra_freight+debit_notes+warranty_cost. With the example figures, 145000.0 + 82000.0 + 19000.0 + 44000.0 + 13000.0 + 23500.0 + 16000.0 gives ₹3,42,500.

How to act: Use the result to review the defect and rework record. Write down the input date and the assumption that could move most.

How to read the result

Example bands, change them for your business:

• Comfortable: Your result meets the target for this item or reporting period. Keep the calculation with its source records and review the defect and rework record.
• Watch: The result is close to your action limit, or it changed since the previous calculation. Recheck scrap cost and rework cost using the original records.
• Act: The result breaks a limit already agreed by the manager or owner. Record the difference, name a responsible person, and agree a correction date. For an operational starting point, read [Too many rejections](/problems/too-many-rejections) and [Quality issue to closure](/processes/quality-issue-to-closure). Do not use these example bands as published industry benchmarks.

Copy it into a spreadsheet

Create a sheet with column A for the label and column B for the number or formula. The expressions work in Excel or Google Sheets. Keep input cells editable and result cells protected from typing.

For any formula containing a divisor, enter a value above zero. For any monetary output, format the cell in Indian rupees. Do not replace the cells with rounded figures until the final display.

What this calculator leaves out

• A low rejection number can hide missed inspections, late customer claims or incomplete records.
• A single average can hide unusual lots, customers or weeks. Review the underlying entries before making a large decision.
• The formula does not check whether the records are complete. Use the same count, lot boundaries and units in both parts of the calculation. Keep rework separate from new output.

Common mistakes

1. Mixing periods. Using scrap cost from one month with rework cost from another produces a number that looks precise but is hard to act on.
2. Trusting old figures. Recheck the relevant source record before reusing last month's saved inputs. Investigate the first repeated defect before accepting an average as normal.
3. Treating an estimate as approval. Record which assumptions were entered by hand. Get the relevant owner, accountant or technician to check unusual values.

A number like this helps only if someone works it out again when things change.

Questions people ask

Where do I find the numbers for cost of poor quality calculator?

Take scrap cost from the latest cost sheet, supplier quote, agreement or invoice. Take rework cost from the latest cost sheet, supplier quote, agreement or invoice. Keep all inputs from the same period.

Can I use this number to approve a purchase or payment?

Use it as a first check. Use the result to review the defect and rework record. Write down the input date and the assumption that could move most. If the result affects tax, legal duties, workplace safety or a major investment, obtain the appropriate review.

When should I calculate it again?

Recalculate when a meaningful input changes, and at the next regular review of the relevant register. Save the date and the input values so changes can be explained.