Every factory quotes a capacity figure, and almost none of them mean the same thing
Ask a sanitaryware factory how much it can produce and you will get a number. It may be described as annual output, monthly output, kiln capacity or container capacity, and it will usually be the largest number the factory can defend. The trouble is not that the number is false. It is that capacity is not a single quantity: it depends on what is being made, in which mix, with which finishes, and on which line. A figure quoted without those conditions is a figure about a plant, not about your order.
For a buyer, the useful question is narrower. It is not “how much can you make” but “what can you make for me, in the window I need, without displacing something you have already promised”. Those are different questions, and only the second one supports a delivery date.
How a capacity figure is actually assembled
In a ceramic plant, output is the result of a chain that has a slowest link, and the slowest link moves depending on the product. The chain runs roughly like this: body preparation sets the amount of slip available, casting sets how many pieces can be formed from the working moulds in rotation, glazing sets the finish throughput, firing sets the hard limit through the kiln, and inspection sets what can actually be released to packing.
Firing is usually the constraint that cannot be argued with, because a tunnel kiln runs a firing curve and the curve is a property of the body, not of the order book. What varies around it is loading density: how many pieces of a given shape fit the kiln car, which changes with size, with height and with how the pieces are set. That is why two factories with similar kilns can quote very different output figures without either of them lying, and why the same factory can quote different figures for two products.
Three columns: the claim, the evidence, and what the evidence does not prove
The diagram below is the frame we suggest a buyer uses when a capacity claim arrives. It separates what is being asserted from what can be checked, and it is honest about the third column, which is the one that keeps a claim from being over-read.
The first row is the kiln, which is usually the real limit and therefore the claim most worth testing. What verifies it is not a photograph of a kiln but the loading record for the firings it has run, together with the firing curve the body requires. What that evidence cannot prove is how much of the kiln’s time is already committed, which is the only part a buyer actually needs. A kiln can be large and full at the same time.
The second row is forming. The verifiable evidence is the number of working moulds in rotation for the shape in question and the shift pattern the plant runs. What it does not prove is that a mould exists for your shape: a plant with generous casting capacity and no tooling for your design will still need to make the tooling first, and that sits ahead of any output figure.
The third row is inspection, and it is the row buyers skip. A plant that can fire a large quantity but release a smaller one has a release capacity, not a production capacity, and the difference is what arrives intact and documented. Inspection records and a reject log are what verify it. What they cannot prove is that the reject rate on your particular model will match the rate on the models in the log, especially on a first run.
The three checks that turn a claim into a plan
Three questions, asked in this order, convert a quoted figure into something a buyer can schedule against:
- Ask for the mix, not the total. A capacity figure should be attached to a product family and a finish, because colour and matt runs are slower than white and carry a per-model minimum of 30 pieces. A single total conceals that entirely.
- Ask what is already booked into your window. The answer is usually a range rather than a figure, and a factory that can describe its order book by month is a factory that plans rather than promises.
- Ask what happens to your order when a larger one arrives. The answer describes the priority rule the plant actually uses, and it is more informative than any output figure.
None of those questions requires the factory to disclose a commercial secret. They require it to describe how it schedules, which is precisely the information a buyer needs and rarely asks for.
Why the number on the website is the least useful version
Published capacity figures exist for search engines and for first contacts, and they are almost always annualised totals under ideal conditions: the plant running its best-selling white model, at full loading density, with no colour changes and no new tooling. A buyer whose order is a colour finish on a model the plant has not run before is not buying that number. They are buying a share of a line, after a changeover, with a learning curve on the first firing.
This is not an argument against asking for the figure. It is an argument for treating it as a starting point and then narrowing it twice: once to your product family, and once to your delivery window. The narrowed figure will be much smaller and much more useful, and a supplier who resists narrowing it is telling you something about how it plans.
What we will and will not claim about our own plant
Our plant is at Chaozhou in Guangdong, built in 2021, on 51,000 m² with 285 people, and it runs its own tunnel kiln. Body preparation, casting, glazing, firing and QC happen in the same factory, which is the arrangement that makes a capacity conversation possible at all: when the kiln and the casting floor are inside one boundary, a question about a delivery date has an answer rather than a handover.
What we will not do is quote a plant-wide output figure as if it were available to one buyer. We will tell you what the range covers — 89 vitreous china models across two-piece, one-piece, wall-hung, back-to-wall, smart, bidet and accessible types — which of them are running, what a colour or matt finish does to the schedule at a per-model minimum of 30 pieces, and what the production lead time of 30–40 days assumes. Where the answer depends on the order book, we will say that it depends on the order book.
The documents that back the plant claims are the ones we publish: ISO 9001 for the quality system, the AS 1976 report recording 0.14% water absorption, CE on the wall-hung models, WaterMark and the WELS rating for Australia, and SGS VOC reports where a project needs them. Certificate documents on request.
Frequently asked questions
Why do two factories quote such different capacity figures?
Because they are counting different things: annualised totals, kiln throughput, or container capacity, each under different assumptions about product mix and loading density. A figure is only comparable once it is tied to a product family, a finish and a period.
Is the kiln always the constraint?
Usually, because the firing curve is fixed by the body and cannot be compressed for a rush order. But casting or inspection can be the constraint on a complex shape or a heavily finished order. The honest answer is that the slowest link depends on what is being made.
What single document best tests a capacity claim?
The loading record for recent firings, read alongside the order book for the window you need. The first shows what the plant actually does; the second shows what is left. A capacity figure without both is a description of equipment rather than of availability.
Does a large plant guarantee a shorter lead time?
No. A large plant with a full order book can be slower than a smaller one with space in its schedule. What a plant’s size affects is how much it can absorb when something goes wrong, which matters later in the order rather than at the quotation stage.
How does a colour finish change the answer?
A colour or matt finish interrupts the white run, needs its own changeover, and carries a per-model minimum of 30 pieces. That makes small colour orders slower per piece than white ones, which is exactly the effect a plant-wide capacity figure hides.
Should I visit to verify capacity?
A visit helps, but it verifies the plant rather than the schedule: you can see the kiln and the casting floor, not the order book. Ask for the scheduling conversation in writing as well, since that is the part a visit cannot show you.
Related on this site
Documents and certificates
Related reading
- Auditing a sanitaryware factory remotely
- What a sanitaryware lead time is made of
- Changing Suppliers Mid-Project