For manufacturers, the cost of quality never really sits still. Every day, teams weigh tradeoffs i.e. speed against accuracy, consistency against flexibility, reacting to problems against preventing them. These decisions don’t stay in spreadsheets. They shape how products are built, how teams run, and what customers ultimately experience.
The trouble is, most organizations don’t actually see what quality costs them. Not in hours. Not in materials. And not in the opportunities that slip away because of rework, delays, or missed insight.
You can’t change what you can’t see. The first step is getting that visibility.
What is Cost of Quality?
Cost of quality (CoQ) is a method for calculating the costs companies incur ensuring that products meet quality standards, as well as the costs of producing goods that fail to meet quality standards.
The goal of calculating the cost of quality is to create an understanding of how quality impacts the bottom line. Whether it’s the cost of scrap and rework associated with poor quality, or the expense of audits and maintenance associated with good quality, both count. Cost of quality gives manufacturers an opportunity to analyze, and thus improve their quality operations.
This two-pronged approach to quality can be categorized as “control” (good quality) vs. “failure of control” (bad quality).
Example of what's included in Cost of Quality
To illustrate what is factored in to cost of quality, let's look at a chocolate manufacturer. Some costs that might be tracked include:
Sourcing high-quality ingredients
Training staff on chocolate-making techniques
Regular inspections for quality control
Calibrating machinery for consistent results
Defective chocolate products
Production issues due to equipment malfunction
Rework due to production errors
Customer refunds or order returns
Gain control of quality escapes and costs
Error-proof inspection steps, track defects and rework, and ensure only high-quality materials and parts move downstream.
Calculating the Cost of Quality
The cost of quality is quantifiable. The method for calculating COQ varies from business to business. However, the basic equations are the same:
Cost of Quality (COQ) = Cost of Good Quality (COGQ) + Cost of Poor Quality (COPQ)
Cost of Good Quality (COGQ) = Prevention Cost (PC) + Appraisal Cost (AC)
Cost of Poor Quality (COPQ) = Internal Failures Cost (IFC) + External Failures Cost (EFC)
Businesses can clearly define the cost of quality with this equation:
COQ = COGQ + COPQ = (PC + AC) + (IFC + EFC)
Understanding the Components of the Cost of Quality (COQ)
There are generally four types of cost of quality, bucketed into two categories:
Cost of Conformance
Cost of Non-conformance
Cost of Conformance
This is the cost a business incurs while ensuring that its product meets quality standards. The cost of conformance includes two costs:
Prevention Cost
As its name suggests, this expense covers activities that prevent poor product quality. A company takes a pre-emptive approach to addressing potential quality problems early to eliminate or at least reduce quality issues later. The goal is to stop, or decrease the likelihood of, having defective goods, manufacturing errors, or wastage. A company incurs prevention costs before launching the manufacturing operation.
Prevention costs include:
Training
Quality planning
Quality assurance
Establishing product requirements
Appraisal Cost
This cost reflects the activities a business engages in to inspect a product for defects. It does this before product delivery.
Appraisal costs include these processes:
Quality auditing
Product verification
Supplier rating
Project managers rely on more preventive controls for better quality. It is a better way to ensure a defect-free product and save money than identifying quality issues after production.
Cost of Non-Conformance
Businesses incur non-conformance costs when their product fails to meet defined quality standards. These failure costs fall under two types:
Internal Failure Costs
After a company identifies defective goods, it can scrap or rework these products. This process falls under the category of internal failure cost. Identifying defects internally ensures only quality goods reach the customer.
Internal failure costs cover the following:
Product rework or modification
Scrapping defective goods
Downtime due to equipment malfunction, errors, or poor management
External Failure Costs
A company incurs external failure costs long after the defective product has left the production facility. This means the company failed to detect the defective product and delivered it to the customer.
This incurs costs like repairs, warranty claims, and replacements, which the company will bear. External failure costs may also include other intangible liabilities such as:
Damaged reputation and loss of sales due to negative product reviews
Loss of future business opportunities with customers due to mistrust
While these aren’t quantifiable, they affect the company’s profitability.
A company can reduce its external failures by asserting control over internal quality measures. When faced with external failures, acting quickly to rebuild customer relations can ease future losses.
CoGQ vs CoPQ: Examples at a Glance
Here’s a quick reference table that compares each cost type, with real examples and where to find the data.
Category | Type | Examples | Where to Find the Data |
Cost of Conformance (CoGQ) | Prevention | Operator training, supplier audits | Training logs, supplier scorecards |
Appraisal | Quality inspections, test station checks | MES, QMS, inspection records | |
Cost of Poor Quality (CoPQ) | Internal Failures | Scrap, rework, unplanned downtime | Shop floor apps, production reports |
External Failures | Warranty claims, customer complaints | CRM, returns database, service logs |
How to Measure CoQ in Practice
Understanding CoQ is one thing and measuring it across your operations is another. The data is out there, but it’s often scattered across different systems.
Here’s where you’ll typically find it:
ERP systems: warranty claims, returns, customer credits
MES / QMS platforms : scrap, rework, inspection results
Shopfloor apps: operator checks, defect logs, downtime reports
Sensors and machines: yield, cycle time, process capability data
Pulling these together gives you the building blocks for a CoQ calculation.
The challenge here is that most companies underestimate their true CoQ because they only track the obvious line items. Hidden costs like overtime to recover from quality issues, lost throughput from downtime, or firefighting resources pulled away from continuous improvement and rarely make it into the calculation. Yet these often account for a large share of the impact.
This is where digital tools make the difference. Instead of waiting for quarterly audits or relying on manual spreadsheets, frontline apps can capture quality data in real time. Every inspection, rework, and failure is logged automatically, giving you a complete picture. With Tulip, that data isn’t siloed, it connects operator inputs, sensors, and machines, so CoQ becomes a living metric you can actually act on.
The Significance of Quality Costs in Business
The manufacturing landscape is becoming increasingly competitive. Customers and clients have numerous options, which means businesses are held to higher quality standards than ever before.
The cost of poor quality (COPQ) has a significant impact on a company’s profitability. Higher poor quality costs can edge it out of the competition. Poor quality products can damage a company’s reputation profoundly. Only when a business takes its defects, errors, and manufacturing missteps seriously can it hold its own among others.
Besides tangible costs, businesses must also consider missed sales opportunities because of customer distrust. Taking steps to ensure good quality at the outset incurs fewer costs than restoring customer relationships or correcting errors later. Doing so will significantly reduce the cost of poor quality. It will also help businesses build a good track record in their niche.
Role in Strategic Decision-Making
Accurately and consistently measuring the cost of quality is a win-win for companies. It helps detect gaps in quality performance and identify essential areas for improvement. Using this information, businesses can make better management decisions. They can invest in targeted training initiatives and commit resources to possible problematic stages of the product lifecycle.
Using quality cost data can help businesses determine the true profitability of their product.
Quality Costs and Customer Satisfaction
External quality issues can amplify associated costs. For example, a company can lose potential business due to negative reviews about its product. Or, a batch of defective products can result in mounting warranty or repair claims.
A better way to ensure customer satisfaction is to address quality issues before they attract external attention. It is much easier to internally identify and resolve quality issues.
Reducing the Cost of Quality
CoQ puts a number on what poor quality really costs. The real benefit comes from driving that number down. Cutting inspection budgets or pushing teams to do more with less usually backfires. The bigger gains come from tackling problems before they reach the line.
A few places to start:
Invest in prevention. Operator training, supplier quality controls, and strengthening process capability usually pay back more than chasing defects after they appear.
Move inspections off paper. Paper checklists delay feedback and bury issues until they become harder to fix. Digital inspections flag problems right away and keep standard work visible.
Watch First Time Quality (FTQ). Tracking how often work passes without rework points to weak spots in the process and gives teams a concrete target to improve.
Make performance visible. Dashboards that update in real time let operators and supervisors react to small shifts before they grow into major disruptions.
Tools like Tulip make these practices easier to roll out and sustain. Frontline apps guide operators through checks, log defects as they happen, and link directly to machines and sensors. Data flows into dashboards instantly, so you’re not waiting for a weekly report but you’re acting on what’s happening at the moment. That shift keeps hidden costs from piling up, raises FTQ, and helps move quality management from damage control to prevention.
Conclusion
Companies should be proactive in managing the cost of quality and heavily invest in prevention and appraisal costs in order to reduce exposure to both internal failure and external failure costs. This can be achieved by a variety of methods such as machine monitoring or adoption of IIoT technology.
-
You’ll need to categorize quality-related expenses into four groups: prevention, appraisal, internal failures, and external failures. Pull costs from systems you already use i.e. ERP for customer returns and credits, MES/QMS for scrap and rework, shopfloor logs for downtime, and machine data for yield and cycle times.
-
Because many quality costs don’t show up as direct expenses. Things like overtime to fix defects, lost throughput from line stoppages, or reputational damage from recalls rarely appear on a P&L, but they drain profitability.
-
CoQ isn’t a one-time calculation. Most manufacturers track it quarterly or annually, but best practice is to measure it continuously so you can spot trends, compare improvement initiatives, and link quality performance directly to financial results.
-
Start small. You don’t need a fully instrumented line to begin. Even a simple app tracking rework and inspection results by shift can uncover meaningful insights. Build from there i.e. capture what’s manual, digitize it, and scale as you go.
-
Absolutely. While they may not be easily quantifiable in dollars, customer complaints, NPS scores, and return rates are often leading indicators of external failure costs, and can trigger improvement projects before revenue is lost.
Reduce your cost of quality with Tulip
Reduce the cost of scrap and rework with apps that help digitize workflows, automate data collection, and improve production efficiency.