Dr. Paul Borosky, DBA, MBA
Business Plan Writer & Financial Projections
Quality Control vs Quality Assurance: What Is the Difference?
Catching Mistakes and Preventing Them Are Two Different Jobs.
Returns are climbing, so you inspect more. Orders still go out broken. The problem might not be how hard you check. It might be where. Read on for the difference between quality control and quality assurance, and which one to fix first. It comes from 14+ years of client work by business consultant Dr. Paul Borosky, DBA, MBA.
Last Updated: 11/08/2026 · Written by Dr. Paul Borosky, DBA, MBA
The Definition
What Is the Difference Between Quality Control and Quality Assurance?
Short Answer
Quality control checks finished work or products to catch problems before they reach the customer. Quality assurance changes the process so problems are less likely to happen at all. Quality control finds defects; quality assurance prevents them. Most growing businesses need both, but fixing the process usually saves more than adding inspections.
QC = check the output. QA = fix the process that makes it.
Doctor Owl, in Plain English
“You can check every parcel at the door and still lose them on the boat. Find where they break, then fix that.”
How This Guide Works
Need the answer fast? Read the Short Answer above and the numbered steps. Want the full picture? Follow Otto, an octopus with a parcel shop from Dr. Paul’s Fabled Forest Business School Series, as he checks harder at the door while parcels break on the ferry. His story shows up in a few short gold notes along the way. The math sits in one section, clearly marked.
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Meet Otto: Checking Harder in the Wrong Place
Some lessons stick better as a story. Dr. Paul’s Fabled Forest Business School Series teaches business through a forest full of small business owners. Doctor Owl, a dry-witted consultant who lives in the Lone Oak, helps them fix the same problems real owners face.
Today he sees six damaged parcels from Eight-Arm Errands in the post office return basket. Otto the Octopus runs the shop at the ferry landing. Business has nearly doubled, and returns have jumped from one in a hundred to six. Otto’s first fix was to inspect every parcel himself at the door.
Why It Matters
Why Does Checking Harder Not Always Fix Quality?
When quality drops, the natural reaction is more inspection. Inspection catches some problems, but it does not stop them from happening, and it slows everything down.
If the cause is somewhere after your inspection, in shipping, handling, or a supplier, more checking at your door changes nothing. That is the gap between quality control and quality assurance.
In the Fabled Forest
Otto checked every parcel himself for two days. On the second day, the boat left with forty still on the dock waiting for him. Returns kept coming.
Know the Difference
When Do You Need Quality Control vs Quality Assurance?
- Quality control fits when defects are random and catching them before shipping is enough.
- Quality assurance fits when the same defect keeps happening for the same reason.
- Start with counting. Sort failures by cause. One or two causes usually dominate. See root cause analysis.
- Fix causes with QA, catch the rest with QC. Then track your defect rate.
In the Fabled Forest
Otto’s bookkeeper sorted 84 returns by cause. Fifty-six were crushed from the top, all on the ferry, where heavy crates were stacked on lighter ones. Eleven were unpadded glass. Three were wet.
Fix It
Which Quality Fix Should Come First?
Fix the biggest cause first, with QA. A process change at the source removes the problem for every order, without adding inspection time. Then set QC to match the risk: check every high-risk item and sample the rest.
Owners often do the opposite, because inspection feels like control. But inspection treats symptoms. The process change cures them.
In the Fabled Forest
The ferry crew agreed to post loading rules in the hold: heavy crates on the bottom, fragile on top. Otto checked every fragile parcel and sampled one in ten of the rest. In three weeks, returns fell back to about one in a hundred, at nearly twice the volume.
The Numbers
Which Fix Removed More Damage?
Here is Otto’s May, sorted by cause, with the fix that matched each one.
| Cause | Damaged in May | Fix | Type |
|---|---|---|---|
| Crushed on the ferry | 56 | Loading rules in the hold | QA (process) |
| Glass without padding | 11 | Check every fragile parcel | QC (inspection) |
| Wet | 3 | Covered storage | QA (process) |
| Other | 14 | Sample one in ten | QC (inspection) |
| Total | 84 |
Step 1: The big cause. 56 of 84 returns, two out of three, came from one handoff Otto never saw.
Step 2: The right tool. No amount of checking at the door would have stopped crushing on the boat. A process change did.
Step 3: Your version. Sort a month of failures by cause. Put a QA fix on the top cause and QC on the rest.
Illustrative numbers from the book. Use your own failure data.
Step by Step
How Do You Use QA and QC Together?
Four steps when quality slips.
Count every failure for a month.
Returns, complaints, and redos, with the cause of each.
Fix the top cause in the process.
That is quality assurance.
Check high-risk items every time.
That is quality control.
Sample the rest and track the rate.
Check a set share and watch the trend.
In the Fabled Forest
Doctor Owl’s scroll for Otto asked three things: where it breaks, how much to check there, and what to count.
Otto’s Full Story
Where Were the Parcels Breaking?
This page gives you the short version. The book gives you the whole month: a basket of returns at the post office, eight arms checking at the door, forty parcels left on the dock, a page of causes in a turtle’s careful hand, and loading rules in the ferry’s hold.
Every chapter of Growth for Small Businesses works the same way. One owner, one problem, one real idea you can use on Monday, plus a one-page worksheet to do it.
A Business Consultant’s View
Should a Growing Business Fix QA or QC First?
Dr. Paul Borosky, DBA, MBA · Business Consultant
When a growing business asks whether to fix QA or QC first, Dr. Paul asks for one month of failures sorted by cause. If one or two causes account for most of the problems, the answer is QA: change the process at the source. That usually removes more defects in a week than months of extra inspection. QC then becomes targeted, every time for risky items and sampling for the rest, so it does not slow the business down. Owners who skip the counting tend to add inspectors and still see the same returns, because they are checking hard in the wrong place.
FAQ
What Gets Asked Most About Quality Systems?
What is the difference between quality control and quality assurance?
Which should a small business focus on first?
How do I find the cause of quality problems?
Keep Going
More on Building Quality In
This term comes from Book 7, Growth for Small Businesses. New to a term on this page? Every one is in the growth glossary.
Written by Dr. Paul Borosky, DBA, MBA, business consultant and author with 14+ years of experience and 1,000+ clients served. Weighing a growth move and want a second set of eyes? See business consulting and prices.
This page is for general educational purposes only. It is not legal, financial, employment, or other professional advice. Figures are illustrations. The Fabled Forest and its characters are fictional. For decisions about your own business, consult a qualified professional.