Factory audits are often reduced to a checklist.
How many employees? How many machines? Which certifications? How large is the workshop? Who are your customers?
These questions are easy to ask, and most factories are well prepared to answer them.
But they don't necessarily tell you whether the factory is right for your project.
A factory can have 500 employees, hundreds of machines and impressive certifications—and still be unable to deliver your customized equipment reliably or scale up when your order volume increases.
So the real question isn't:
“Is this a good factory?”
It is:
“Can this factory consistently deliver what I need, at the volume, technical specification and delivery schedule I require?”
That requires looking beyond what the factory has and understanding how it operates.
1. “How much of your current business is technically similar to our project?”
This is one of the first questions I would ask.
Not:
“Can you make this?”
Almost every factory will say yes.
A better question is:
“How much of your current production is technically similar to what we need?”
A pump manufacturer may have 20 years of experience making pumps. But if most of its business is standardized products, that doesn't necessarily mean it understands your specific medium, pressure, temperature, material requirements or operating conditions.
On the other hand, a smaller factory that has spent years building similar customized equipment may be a much better fit.
Product experience is not the same as application experience.
2. “What type of customers do you normally serve?”
This question reveals something that a factory website rarely does:
Where would we actually sit in your customer structure?
Does the factory mainly serve:
Large OEMs?
Distributors?
EPC contractors?
Small and mid-sized industrial companies?
Overseas project customers?
Customers requiring customized equipment?
There is no universally “better” customer profile.
But there is a customer profile that is better suited to your project.
A factory built around large OEM orders may be excellent at high-volume, standardized production.
But if you need five customized machines and expect several design changes along the way, that same factory may not be the right fit.
Customer structure is part of supplier capability.
3. “What happens if the drawing changes after production starts?”
For customized industrial equipment, this is a critical question.
Because in real projects, specifications rarely remain completely unchanged from the first drawing to final delivery.
Ask:
“If we change a dimension or replace a component after production has started, what happens internally?”
Don't just listen to the answer. Look at the process behind it.
Who approves the change?
Who updates the drawing?
Who updates the BOM?
How does purchasing know?
How does production know?
How does quality control know?
A mature factory doesn't simply rely on:
“Our salesperson will tell the workshop.”
The change should enter a controlled process.
Drawing updated.
BOM updated.
Production documents updated.
Purchasing informed.
Quality requirements synchronized.
Every step leaves a record.
For customized equipment:
Document control is part of manufacturing capability.
4. “Can you show us how you trace a product through production?”
Don't just ask:
“Do you have a traceability system?”
Ask them to demonstrate it.
Choose a finished product at random and ask:
Where did the material come from?
Who processed it?
What inspections were performed?
Which critical components were installed?
What tests were completed?
Can the records be traced back to the original order?
You don't necessarily need sophisticated software.
A simple system can work perfectly well if people actually use it consistently.
What matters is whether the factory can reconstruct:
how a product was made, inspected and released.
For overseas buyers, this becomes even more important.
You cannot stand on the factory floor every day.
You see the result.
The records give you visibility into the process.
5. “What was your last significant quality problem?”
This question can be more revealing than:
“What is your quality pass rate?”
No factory wants to tell a potential customer that it has quality problems.
But asking about the last significant problem changes the conversation.
What happened?
Why did it happen?
How was it discovered?
What was the root cause?
What changed afterward?
A mature manufacturer doesn't pretend that problems never happen.
What matters is whether the organization can learn from them and change the process.
How a factory deals with failure often tells you more than how it presents success.
6. “Which parts do you actually manufacture yourselves?”
This is particularly important when evaluating manufacturers in China.
A company may present itself as a manufacturer while outsourcing a significant portion of its production.
That isn't necessarily a problem.
One of China's manufacturing strengths is its dense network of specialized suppliers.
A capable industrial integrator may outsource machining, casting, surface treatment or electronics while keeping control of:
engineering, critical components, assembly, testing and project management.
The important questions are:
“Which capabilities do you control internally?”
and:
“Which critical processes depend on external suppliers?”
Then go one step further:
“Which outsourced processes could affect our product performance or delivery?”
Now you're looking beyond the factory itself and into the real manufacturing network behind the product.
7. “What is your current capacity—and how much can you add?”
This is one of the most underestimated questions in large-volume sourcing.
Many buyers ask:
“How many units can you produce per month?”
It's important.
But it only tells you what the factory can produce today.
A more important question is:
“If our order volume increases by 30%, 50%, or even 100%, how would you respond?”
Now you're evaluating something different:
capacity flexibility.
Look at:
Current utilization of critical processes
Available capacity
Bottleneck operations
Ability to add shifts
Backup equipment
Critical component availability
Dependence on single suppliers
Subcontractor capacity
Peak-season production planning
Lead time required for expansion
These questions can tell you much more than:
“How many CNC machines do you have?”
A factory may have 100 machines and still have very little effective capacity if one critical process is already running at 95% utilization.
The real constraint is often the bottleneck, not the total number of machines.
That's why capacity should be viewed in at least three ways:
Installed Capacity What the factory has.
Available Capacity What it can realistically produce now.
Flexible Capacity What it can reliably add when demand changes.
For large-volume buyers, the third number may be the most important.
8. “If demand increases, how exactly would you expand production?”
This follows naturally from the capacity question.
A factory with real flexibility usually has several ways to respond:
Add shifts → Rebalance production → Add workers → Add equipment → Increase outsourcing → Expand production space
Every factory has a different expansion model.
Some factories already operate close to full capacity. When orders increase, the only answer they can give is:
“We need more time.”
Others may have lower current utilization but a well-developed system for scaling production.
That factory may be a much better long-term partner.
Because:
Capacity is not a number. It is a system's ability to absorb change.
9. “Who is actually responsible for our project?”
Don't simply accept:
“Our sales manager will take care of you.”
Industrial equipment projects usually involve multiple functions:
Sales → Engineering → Purchasing → Production → Quality → Testing → Shipping → After-sales
You need to know who owns each stage.
More importantly:
“If something goes wrong, who has the authority to make the decision?”
A factory can have excellent equipment, engineers and quality systems.
But without clear project ownership, the project can still fail.
A mature supplier doesn't just have departments.
It has a system that allows those departments to work together around a project.
The Most Important Part of a Factory Audit Is Not How Many Questions You Ask
After visiting and working with many factories, I've come to believe that the most valuable part of an audit is not collecting the most information.
It's looking for consistency.
Does what the salesperson says match what the engineers say?
Does the documented process match what actually happens on the shop floor?
Does the factory's claimed capability match what you can see in production?
Is the quality system actually being used?
Does its customer structure match the type of project you're bringing?
Does its current capacity match its ability to scale?
These gaps are often more revealing than any individual answer.
A Factory Audit Is Not About Finding the “Best Factory”
This is one of the most important points.
There is no factory that is the best for every project.
A highly automated manufacturer may be exactly right for:
10,000 standardized units.
A smaller engineering-driven factory may be better for:
five customized machines.
An industrial integrator with a strong supplier network may be better for:
a complex system involving multiple technologies.
So a factory audit should not simply produce:
Good Factory / Bad Factory
It should answer a much more useful question:
Good Factory for What?
What type of project is this factory actually built to handle?
For overseas buyers, this distinction matters even more.
You may be thousands of kilometers away, working across languages, time zones and different manufacturing practices.
Supplier selection therefore cannot be based simply on:
“The factory says it can do it.”
You need to understand the manufacturing system behind the product.
Equipment matters.
Certifications matter.
Factory size matters.
Capacity matters.
But what really matters is whether these elements come together into a system capable of reliably delivering what your project requires.
A meaningful factory audit is not about proving that a supplier looks impressive.
It is about finding the answer to one fundamental question:
Is this the right manufacturing capability for my project?
That is what a factory audit should actually be about.