Cost of Poor Quality (COPQ) is the cost incurred because work was not done right the first time. It captures the losses caused by defects, rework, escapes to customers, and all the extra activities that would not exist if processes consistently produced defect-free outcomes. In electronics manufacturing and SMT assembly, COPQ drains profit through scrap, rework labor, line disruptions, returns, and the "hidden factory" of unplanned activities. Although the impact is often substantial, these costs are frequently overlooked or remain unmeasured.
What COPQ Represents
COPQ is the portion of actual operating costs that could be eliminated if every activity proceeded without defects or problems.
Categories of Cost of Poor Quality
Cost of Quality vs. Cost of Poor Quality
Quality-related costs are commonly categorized to provide visibility and a common language for improvement. A useful distinction is between the broader "cost of quality" (which includes prevention and appraisal activities) and the narrower "cost of poor quality," which focuses on the losses tied to defects and failures.
A Paradigm Shift in Viewing Quality Costs
A modern view of quality costs emphasizes building quality into processes up front rather than relying on inspection to catch problems later. This shift aligns investment in prevention with measurable reductions in COPQ, turning quality from a perceived overhead into a direct profit lever.
Sigma Level and COPQ
There is a strong relationship between process capability (Sigma level) and COPQ. As Sigma improves, defect opportunities shrink and COPQ declines, often nonlinearly. Higher capability reduces failure costs, fewer escapes reach customers, and less inspection is needed to maintain outgoing quality.
Why Analyze COPQ?
- Enable identification and quantification of quality-related costs.
- Expose the Hidden Factory—unseen rework, retest, sorting, and firefighting activities that consume resources.
- Provide one of the fastest paths to profit growth by systematically reducing COPQ.
- Offer a data-driven tool to prioritize problems, track changes, and measure improvement progress.
Prevention Costs
Prevention PCB costs are incurred to avoid defects before they occur. They are intentional investments in doing work right the first time and are not part of COPQ.
Examples include:
- Quality planning.
- New product reviews and design evaluations.
- Process planning.
- Process control and quality control plan development.
- Quality audits and layered process audits.
- Supplier quality assessments and development.
- Training and competency development.
Appraisal and Inspection Costs
Appraisal costs arise from activities performed to detect defects before they affect customers. These are the checks and tests used to assess conformance.
Examples include:
- Pre-shipment testing of consumer products (reliability tests, component inspections, precision measurements, final outgoing inspection).
- Inspection prior to dispatching pharmaceuticals under insurance management.
- Incoming inspection of purchased equipment and materials.
- Correction and verification of reports and correspondence.
- Checking tax invoices for errors before sending them to consumers.
- Vehicle inspections to confirm whether repair is necessary.
Internal Failure Costs
Internal failure costs are incurred when defects are found before the product reaches the customer. Customers do not directly see these failures, but they degrade service and delivery and absorb significant resources.
Examples include:
- Rework and retest due to nonconforming lots.
- Repair due to product defects found in-house.
- Scrapping obsolete or discontinued materials.
- Microcontroller or control-program modifications.
- Replacing nonconforming metal stamping parts.
- Unplanned supplemental work due to unexpected computer or equipment failures.
- Replacing products damaged during packing or shipment staging.
- Overtime required to finish work that was not completed within standard time.
- Correcting numerous database errors.
- Maintaining additional inventory to replace defective components.
- Scrapping products that exceed specification limits.
External Failure Costs
External failure costs occur when defects escape to the customer. These are directly experienced by customers and often dominate COPQ due to lost sales, warranty, and reputation damage.
Examples include:
- Ship-backs, scrap, or discounted sales due to failure to meet safety regulations or product liability criteria.
- On-site rework and field recalls resulting from high defect rates.
- Investigation and handling of customer complaints.
- Concessions or offsets offered to recover dissatisfied strategic customers.
- Correcting errors in issued tax invoices.
- Expedited shipping costs caused by delivery delays.
- Replacement and repair for goods damaged in transit.
- Accommodation costs for passengers due to flight cancellations or delays.
Team Exercise
For the processes within your team, identify activities that generate COPQ and classify them as follows:
- Appraisal/Inspection Costs
- Internal Failure Costs
- External Failure Costs
Applying COPQ in Projects
When COPQ Is Most Useful
- Project prioritization: rank projects by potential COPQ reduction.
- Focusing on the vital few: after identifying the vital few Xs (key drivers), target improvements where COPQ impact is highest.
- Demonstrating project impact: quantify benefits by translating improvements into COPQ reduction.
- Selecting countermeasures: compare improvement costs against projected COPQ savings to choose effective actions.
How to Measure COPQ
Measure COPQ in a structured sequence:
- Identify activities triggered by defects or nonconforming product.
- Define the cost measurement method for each activity.
- Collect data and estimate costs.
- Analyze results to prioritize actions and monitor improvement.
In SMT factories, a disciplined COPQ approach brings hidden waste to light, aligns teams on the true economics of defects, and directly links process capability to financial outcomes. By classifying costs consistently, measuring them transparently, and acting on the largest contributors, organizations can turn quality into a sustainable competitive advantage and a reliable source of profit improvement.
