The price was right and the sample was good, so why is delivery slipping?
Vetting a Factory's Production Capacity to Cut Delivery Risk

Hello, this is Green Frog Seoul.

“The price fit, the sample was good, so we signed, and then the goods just don’t come out in peak season.”
“I chase them at the deadline and all I get back is ‘other orders are backed up, there’s no line right now.’”
“The factory looked big and solid, but our goods always seem to get pushed to the back.”
“The first small order was spot on, but the moment we scaled the volume, deliveries started falling apart.”

When choosing a factory, we scrutinize price and samples. But the one thing we tend to take on faith is whether this factory has the muscle to make our volume on time. A slick factory photo and a confident “no problem” from the boss, and the vetting stops there. Only after deliveries slip in peak season do we realize, too late, “this factory could only ever make about this much.”

Today we talk about a factory’s production capacity, commonly just called “capacity.” If price and quality are the questions of “at what cost and how well does it make this item,” capacity is the question of “how much and how fast can it make it.” Look only at the first two and skip the third, and the contract goes smoothly while the deadline trips you up.

A lot of delivery disasters happen not because the factory is lazy but because the order went into a place that never had the capacity in the first place. No amount of chasing pulls goods out of a factory that lacks the muscle to make them. So before you ask “how fast can you make it,” confirm “is this factory a vessel big enough to hold our volume.”

This guide covers, in order, what capacity is, why the capacity a factory states differs from its real capacity, the four elements that set capacity, how much of that factory your order actually is, the mechanism that pushes your goods back in peak season, what to verify on an audit, and a worked example of reverse-estimating capacity in numbers.

1. The third axis you miss when you look only at price and quality

When choosing a supplier, most people look at two things. Is the price right, and does the sample quality hold up. These two get verified naturally because you can confirm them with your own eyes before signing. The problem is the third axis: capacity. Capacity is hard to see at signing, and its true nature only shows up later, when volume grows and orders pile up.

Price, quality, and capacity are the three legs of choosing a factory. Take any one away and the stool tips over. A great price is wasted if goods don’t arrive on time and you lose the sale; great quality is wasted if supply cuts off in peak season and you lose the account. Yet in practice this third leg often gets waved through with “surely they can make it.”

2. Theoretical capacity and effective capacity are different

Ask a factory “how many a month can you do,” and you usually get a big number back. But that number is mostly theoretical capacity, the maximum figured on the assumption that no machine ever rests, there are no defects, and people are on it around the clock. Reality never yields that number.

What you actually get is effective capacity. Equipment loses time to maintenance, tooling changes, and breakdowns; a portion of what’s made drops out as defects; and there’s a limit to the shifts people can staff. Effective capacity is theoretical capacity minus these losses, and the volume you can really receive is close to this.

Fail to tell whether the factory’s stated capacity is theoretical or effective, and you place an order trusting “100,000 a month” only to receive 60,000. So when you ask about capacity, don’t ask for a single number, ask under what conditions that number was produced.

3. The four things that set capacity

Effective capacity isn’t a number that falls from the sky; it’s the product of four elements. Break these four apart and you can check for yourself whether the capacity the factory named makes sense.

Equipment is the vessel of capacity. A factory with two injection machines and one with ten differ fivefold in output for the same product. But don’t just count machines, look at how many are the right size and spec for your product. Ten big machines are no help if only two accept your tooling; then those two decide your capacity.

Speed is cycle time. A part that takes 30 seconds per shot and one that takes 60 differ twofold in output on the same equipment. A multi-cavity mold that yields several pieces per shot raises speed accordingly. Run time is how many shifts a day (usually 8–12 hours per shift) and how many days a month it runs. Finally, uptime and yield shave all of this down. Reflect the time equipment sits stopped (uptime) and the share thrown out as defects (yield) to get what actually lands in your hands.

4. What percentage of that factory is your order?

Here is the point beginners miss most: assuming the factory’s entire capacity is yours. A factory doesn’t make only your goods. It shares its lines across other clients’ orders, and your order gets assigned only a slice of the whole.

So the number to really watch isn’t the factory’s total capacity but the share allotted to you within it. A factory that makes 120,000 a month, already 60% filled by other clients, leaves you about 48,000 of headroom. If your order is 60,000 a month, this factory can’t handle your volume regardless of its face-value capacity.

Conversely, it’s also a problem if your order is too small a share of the factory’s total capacity. If you’re a 1–2% customer, you get bumped down the priority list when orders pile up. And if you lean too heavily on one factory (say, over 70%), you have no fallback when that factory hits trouble. Finding the right share, and splitting suppliers when needed, starts here.

5. The mechanism that pushes your goods back in peak season

Some factories hold deliveries fine most of the year and collapse only in peak season. That usually happens because line-assignment priority kicks in the moment capacity falls short of orders. When orders pile up, the factory has to choose which to put on its limited lines first, and whether you’re at the front or back of that queue decides your delivery.

The customers a factory assigns lines to first are mostly fixed. Large, steady accounts; clients who pay fast and clean; long-standing relationships stand at the front. Small-volume, slow-paying, high-demand new clients get bumped to the back. In peak season, “there’s no line” is often a polite way of saying “there are customers we put ahead of you.”

So checking capacity isn’t only a matter of numbers; it’s also a matter of what kind of customer you are at that factory. With the same capacity, if you’re at the front of the priority queue your goods come out even in peak season; at the back, only when there’s slack. To hold peak-season delivery you have to both pick a factory with ample capacity and build the relationship that secures priority there.

6. What to verify on an audit

Capacity can’t be confirmed by asking alone. A factory needs to win the order, so it tends to inflate capacity, and whether that’s true has to be filtered on site. Whether you visit in person, commission a third-party audit, or ask for a live video tour of the line, the points to check are similar.

First, count the equipment with your own eyes. How many machines run the process used for your product, and are they actually running or idle. If many sit stopped, ask whether it’s for lack of orders, breakdowns, or lack of people. Next, look at the people. Are workers on the line, are the shift crews actually there, how do they add staff in peak season. Equipment with no one to run it makes capacity a number on paper.

Finally, look at the records. Ask for the last few months of production output, the main client list, and the status of orders currently in progress. A factory with output records is one that manages its own capacity in numbers, and such factories tend to make realistic delivery promises. A factory that just repeats “we can do it all” and can’t show records is likely speaking of capacity by gut feel.

7. Reverse-estimating capacity in numbers

Now let’s gather the pieces and actually calculate capacity. Take a factory that molds a 200 g product on 5 injection machines. All numbers are assumptions to show the structure.

Break it down this way and you see the factory’s “100,000 a month is nothing” with entirely different eyes. Even if the whole effective capacity is about 118,000, with 60% filled by other clients your share is about 47,000. If your order is 60,000 a month, this factory has to add a shift to extend run time, push out other orders, or, failing that, slip your delivery. Run this calculation before signing and you can discuss concretely with the factory “what has to be in place to receive 60,000 a month reliably.”

8. Reading the signals of too little and too much capacity

Before and after signing, signs of a capacity problem show up in a few patterns. Read these signs early and you can act before a delivery disaster.

The signals of too little capacity usually look like this: deliveries stretch noticeably the moment you scale volume even a little; contact goes quiet and excuses multiply whenever peak season hits; samples and first articles were fast but mass production slows to a crawl; ask about your order’s progress and you get “it’ll be ready soon” instead of a clear schedule. When these signals stack up, the factory may be a vessel too small for your volume.

Conversely, too much idle capacity isn’t simply a good sign either. If most equipment sits idle with almost no orders, the price may be attractive, but you should ask why the factory is so quiet. Sometimes clients left over quality problems, or the factory is in financial trouble. Too busy and you get bumped; too quiet and there’s a reason, so a moderately busy factory is generally the safe bet.

9. Common misunderstandings

Here are the misunderstandings that come up repeatedly when people first weigh capacity.

• Assuming a big, slick factory has ample capacity too (what matters is the equipment fit for your product and the spare line).
• Mistaking the total capacity the factory named as all yours to use (most is shared with other clients).
• Trusting that because a first small order went well you can scale volume too (capacity goes on trial only after you scale).
• Mistaking theoretical capacity for effective capacity (subtract uptime and yield to get what you’ll actually receive).
• Assuming that because off-season delivery is fine, peak season will be too (anyone keeps up when there’s slack).
• Thinking that checking capacity once is enough (a factory’s situation changes, so revisit it periodically).

10. Capacity verification checklist

Before signing

• Confirmed how many machines fit your product and whether they actually run.
• Asked whether the capacity the factory named is theoretical or effective.
• Asked how full the lines are now and how much headroom can be allotted to you.
• Confirmed the last few months of output and the status of orders in progress.

When auditing

• Saw the actual production line and equipment, not the office and sample room.
• Checked not just equipment but the workforce and shift operation.
• Confirmed when the factory’s peak season is and whether it overlaps your selling peak.

During the relationship

• Discussed capacity in advance against the volume you plan to grow into.
• Watching for the signal of delays that repeat and deepen.
• Prepared a second supplier for key items to lower dependence on one factory.

Conclusion: put orders into a factory that has the muscle to make them

The three legs of choosing a factory are price, quality, and capacity. The first two are visible before signing, but capacity shows its true nature only after volume grows and orders pile up. So capacity must be checked in advance, before signing, against the volume you plan to grow into, not your first order.

Two things to remember. One, the capacity a factory names is usually theoretical, so read it as effective capacity with uptime and yield subtracted, and within that, ask for the spare capacity actually allotted to you. Two, capacity is not only a matter of numbers but also of whether you stand at the front of the priority queue in peak season. Even the simple check of multiplying machine count by output per hour, run time, uptime, and yield gives you that baseline. Get these two into your bones and you can dodge the trap where the price and sample were good but the goods don’t come out in peak season.

Green Frog Seoul works with importers making and bringing goods in from China to gauge effective capacity from a factory’s equipment, workforce, and output records, and to weigh the share your volume takes at that factory and its peak-season priority, so you choose a factory that supplies reliably. Judge specific capacity and delivery against the actual equipment list, production records, and on-site verification.