Cost of Quality

Cost of Quality?

cost of quality
cost of quality

What is Cost of Quality (CoQ)?

Cost of Quality is a technique defining and measuring where and what amount of a companies’ resources are being used for prevention activities and maintaining product quality as opposed to the costs resulting from internal and external failures.

Six Sigma lets you work out the cost of quality by estimating:

  • The cost of production of the wasted original product
  • The cost of recall
  • Scrapping or rework
  • The additional work done to rectify the original product
  • The resultant cost of recall
  • The cost of manpower working with the product before, during and after the recall
  • The cost of losing business
  • Negative publicity
  • Their impact on stock price
  • The delay in working on another product or another feature for the same product

If there are litigations and fines, then they add up to the costs as well and can bring a business on its knees. So while it is hard to say how much it costs to make a quality product, it is easier to calculate how much it will cost a company that neglects quality.

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Importance of Cost of Quality

The economic environment is becoming increasingly more competitive. Many companies are promoting quality as the core customer value and consider it to be a key success factor for achieving competitiveness.

There are various alternatives available to the customer for almost every product on the market. The better-performing companies set themselves apart by listening to the voice of the customer and supplying products according to the customers’ requirements while maintaining a high level of quality and dependability. These companies gain their advantage by measuring and reporting the cost of quality (COQ).

The Cost of Quality can be portrayed by the sum of two factors, the Cost of Good Quality (COGQ) and the Cost of Poor Quality (COPQ).


The Cost of Quality incorporates all associated costs with the quality of a product, from preventive costs intended to reduce failures, cost of process controls to maintain quality levels, and the costs related to both internal and external failures.

what is cost of quality
why implement cost of quality

Why Implement Cost of Quality (COQ)?

The efficient utilization and implementation of the Cost of Quality technique enable an organization to assess the number of resources being used for the Cost of Good Quality and Cost of Poor Quality. With this crucial information, the organization can determine where to allocate resources to improve product quality and the outcome.

  • Improve product quality and reduce costs through the implementation of the Cost of Quality technique.
  • Evaluate the effectiveness of quality systems using the Cost of Quality approach.
  • Identify problem areas impacting product quality and cost.
  • Accurately leverage opportunities to enhance product quality and cost-effectiveness.
lowering coq with a modern eqms solution

Lowering Cost of Quality (CoQ) with a Modern EQMS Solution

How to Measure the Cost of Quality (COQ)

Cost of Quality calculation differs from organization to organization. Many times, organizations determine the Cost of Quality by calculating total warranty dollars as a percentage of sales.

But this method looks externally at the Cost of Quality and not internally. For better understanding, a more comprehensive overview of all quality costs is essential.

    The cost of Quality is categorized by:

  • Prevention Cost (PC)
  • Appraisal cost (AC)
  • Internal Failure Cost (IFC)
  • External Failure Cost (EFC)

By applying these four categories to the original Cost of Quality equation, which states that Cost of Quality is the sum of Cost of Good Quality and Cost of Poor Quality, the basic equation can be expanded as shown below:

  • The Cost of Good Quality is the total of Prevention Cost and Appraisal Cost (COGQ = PC + AC)
  • The Cost of Poor Quality is the addition of Internal and External Failure Costs (COPQ = IFC + EFC)

By combining the above equations, the Cost of Quality can be more defined, as shown below:

COQ = COGQ+ COPQ = (PC + AC) + (IFC + EFC)

how to measure cost of quality

What are the Types of Costs of Quality?

prevention cost
Prevention costs

Signify the costs incurred with the efforts taken to prevent the occurrence of defects. Prevention Costs imply the following:

  • Developing a quality management system and the associated quality planning documents
  • Establishing product specifications, new product development based on that, and testing
  • Proper employee quality awareness and training and supplier evaluation
  • An analysis of the quality audit and quality improvement program
quality appraisal cost
Appraisal costs

Represent the costs incurred with inspected tests and performed checks to determine whether the particular requirements are met. Appraisal costs can include the following:

  • Inspections and tests of incoming material and products, finished product acceptance, test equipment purchase, and maintenance
  • Inspection and test documentation and employees’ wages
  • An analysis of the inspection and test results
  • Supplier assessments
internal failure cost
The internal failure costs

Describe the costs incurred to rectify all the nonconformities found before the product supply to the recipient. Internal failure is determined by the following:

  • Heaps of scrap
  • Costs of reprocessing and repeating the tests
  • Performing product remedy, rework and repair operations
  • Product downgrading costs and costs associated with failure analysis
  • Machine breakdown due to inappropriate maintenance and trash due to inadequately designed processes
external failure cost
The external failure costs

Depict the costs incurred to correct all the nonconformities found after the product supply to the recipient. External failure costs indicate the following:

  • Customer complaints and product or material returns
  • Damages due to poor packaging and penalties for delays in deliveries
  • Providing service and repair costs
  • Incorrect sales orders and incomplete BOMs
  • Warranty claims
taguchis loss function
Taguchi’s Loss Function

The Taguchi Quality Loss Function (QLF) is a statistical function, proposed by the Japanese quality expert Genichi Taguchi, which states that the quality loss function is used to estimate costs when the product or process characteristics are switched from the target value. This is represented by the following equation:

L= k(y-T) ^2 where L= Quality loss

y = the actual size of the product

T = Target value

k = Proportionality constant.

This is also known as parameter design, which is a selection of a parameter level to make the process robust against environmental changes with the smallest variation.

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3 Women Leaders Making a Powerful Impact in Global Quality and Safety Management

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What is the Cost of Good Quality (CoGQ) and Cost of Poor Quality (CoPQ)?

The Cost of Good Quality (COGQ) consists of the cost of quality conformance, including any associated costs with both appraisal and prevention, whereas the Cost of Poor Quality (COPQ) involves all the nonconformance costs that are both internal and external to the company.

COGQ: Appraisal Costs (controls implemented by the organization) and Prevention Costs (activities to eliminate defects from ever occurring)

COPQ: Internal Failure Costs (defects occurring and managing within the company) and External Failure Costs (defects that reach the customer)

cost of poor quality

As subject matter experts, they knew exactly how to translate our company processes, and do them more effectively within the application.

Glenn Cann, President,
AOC Global Services and AOC Program Solutions

aoc global services
aoc global services

What are the Ways of Perceiving Cost of Quality

There are several ways of perceiving the Cost of Quality while they can be contradictory towards each other.

reduce cost of quality to improve profit

Reduce Quality Costs and Boost ROI

Your business is transformed in many ways to reduce costs across every level of your manufacturing operations if the quality is embedded within every operation. With a quality manufacturing approach, the cost of quality initiatives become a powerful tool to improve return on investment.

reduce cost of waste

Reduce the cost of waste, scrap, and rework

Relying solely on a final inspection for quality control can be too late. If a process differs from specification anywhere in the production line, that finished product goes directly to the waste bin, accumulating the incalculable costs in rework and materials. You must monitor product and process quality in real-time at every critical operation so that plant operators can adjust and eliminate variations before they cause costly waste.

reduce cost of quality by improving customer satisfaction

Turn customer complaints into customer satisfaction

When you can identify and rectify product and process variations early before your final inspection and reach to customers or if customers are having issues or concerns, then you should provide immediate access to reporting for responding to customer queries quickly. This can build a stronger bond, more repeat orders, and better customer relationships.

quality impacts on brand value

Build brand equity and gain a competitive advantage

Extensive data collection and quality control analysis capabilities, automated alerts, and aggregated access to historical data enable unparalleled product consistency to meet your customers’ expectations and elevate your brand as the premium producer in your industry.

Implement the Cost of Quality while reducing the cost to determine where to allocate resources to improve product quality

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Quality-centric Companies Rely on CQ QMS

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  • janssen mono
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