Every supplier profile states a monthly capacity. Almost none of them survive a site visit. The gap is not usually dishonesty — it is that capacity means different things to different people: theoretical machine capacity, sustainable output at normal working hours, or the best month the factory ever had.
For a buyer, the question that matters is narrower. Not "how much can you make" but "how much of my product can you make per month, at the quality standard I need, without displacing the orders you already have". Answering that requires five checks, and none of them requires an engineering degree.
Start With the Machines That Set the Pace
In bag production the constraint is rarely the sewing machines. It is whichever operation has the longest cycle time per unit — often cutting, skiving, edge painting, or a specialised step such as logo embossing or hardware setting. Counting machines tells you potential; counting the machines at the bottleneck tells you output.
| Department | Typical equipment | Where the constraint usually sits |
|---|---|---|
| Cutting | Clicker press, die cutting, laser, strip cutter | Die cutting for multi-layer; laser for complex panels |
| Preparation | Skiving, edge folding, splitting | Skiving — slow, skilled, and frequently under-machined |
| Stitching | Flatbed, post-bed, cylinder arm, heavy-duty | Usually not the constraint, unless specialised machines are few |
| Edge finishing | Edge painting, burnishing, hot foil | Edge painting — multi-pass, drying time between coats |
| Hardware | Riveting, press, setting machines | Setting of complex hardware assemblies |
| Finishing | Trimming, cleaning, packing | Inspection and packing at peak periods |
Ask how many units per hour the bottleneck operation completes, and multiply. That figure, not the machine count, is the honest capacity number.
Check the Line Balance
A line is balanced when each operation takes a similar time per unit. Unbalanced lines have visible queues — bundles of cut panels waiting in front of one station while the operator ahead sits idle. Walking the floor and looking for work-in-progress piles identifies the constraint in about five minutes, without asking a single question.
Quantify it by timing three operations. If cutting a panel set takes 4 minutes, skiving takes 9 and stitching takes 6, the line's rhythm is set by the 9-minute operation and the rest of the line runs at roughly two-thirds efficiency. A factory claiming capacity based on its stitching machines will overstate output by half on that basis alone.
Look for the piles
Bundles of WIP stacked in front of one station and empty tables in front of others is the whole story. A balanced line has small, even buffers between every operation.
Programme parameters at a glance
| Parameter | Commitment |
|---|---|
| Minimum order quantity | 500 pieces per style / colourway |
| Sampling lead time | 6–10 working days (12–15 days for complex constructions) |
| Bulk production lead time | 35–50 days after sample approval |
| Inspection standard | AQL 2.5 (ISO 2859-1), single sampling, general level II |
| Incoterms | FOB Xiamen — EXW, CIF and DDP available on request |
| Payment terms | T/T 30% deposit / 70% before shipment; L/C at sight for container loads |
| Verified production floor space | 4,950 m² (SGS-verified) |
| Team | 137 staff across 7 production lines |
| Equipment | 149 machines including computerised saddle-stitch and edge-painting units |
| Monthly capacity | 200,000 pieces |
| Entity | Founded 2014; principal has worked in bag development since 2004 |
Reconcile Output Against Consumables and Utilities
Output claims can be cross-checked against inputs that are harder to fabricate. Materials, thread, hardware, electricity and headcount all scale with real production.
- **Thread consumption.** A structured bag uses a predictable length of thread per unit. Monthly thread purchases divided by consumption per bag gives a rough output ceiling.
- **Hardware purchases.** Zip metres, sliders and rivets are bought in countable units and are hard to overstate.
- **Electricity.** A factory running at its claimed output draws a consistent load. A month of meter readings plotted against claimed output should track reasonably.
- **Headcount and attendance.** Ask for the production headcount by line and the attendance records. Output per operator is a stable figure in a given product category.
- **Shipping records.** Bills of lading for the last three months show what actually left, which is the only capacity figure that has already been proved.
Separate Capacity From Availability
A factory can have ample capacity and none available to you. Capacity already committed to other customers is not capacity, and this is the most common misunderstanding in a first conversation. Ask directly what proportion of each line is committed for the next three months, and who the anchor customers are.
The follow-up question is about seasonality. Bag production has a pronounced peak running into the gifting and travel seasons, and a factory that can take a February order comfortably may be unable to take a September one. Ask for the last twelve months of output by month; the shape of that curve tells you when your order will be squeezed.
| Question | What a good answer looks like | Red flag |
|---|---|---|
| Committed load next 3 months | A percentage per line, with named anchor customers | "We have plenty of capacity" with no numbers |
| Output by month, last 12 months | A curve with a visible seasonal peak | A flat line, which usually means estimates rather than records |
| Peak lead time | A stated extension, e.g. 35–50 days becomes 55–65 in peak | "Lead time never changes" |
| Subcontracting | Named, audited subcontractors for defined operations | Denial, followed by unexplained WIP volume |
Subcontracting is normal in the industry and not a defect. The defect is undisclosed subcontracting, because it moves quality control outside the factory you audited.
Assessing Quality Capacity, Not Just Volume
A line that can make 5,000 bags a month at a ninety percent first-pass yield is more useful than one that makes 7,000 at seventy percent, because the difference is rework, and rework consumes the same capacity as production. Ask for the first-pass yield by line and the rework rate.
The second quality-capacity indicator is inspector ratio. A factory running a genuine AQL 2.5 inspection needs inspectors who are not also sewing. Ask how many people are dedicated to inspection, how defects are recorded, and whether the records are available for review. A factory with no defect data cannot be managing yield, whatever it claims.
A Five-Hour Audit That Produces a Number
The whole exercise can be compressed into a single site visit if it is structured.
- Walk the floor and count machines by department, noting the specialised machines specifically.
- Time the three slowest operations and identify the constraint; calculate units per hour from it.
- Ask for last twelve months of output by month and the committed load for the next three.
- Reconcile against thread, hardware and electricity purchases, and against recent bills of lading.
- Ask for first-pass yield, rework rate and the inspector headcount, and ask to see a defect record.
- Photograph the WIP buffers at each station; the photographs are the most persuasive part of the report.
Where the Programme Fits
QUANZHOU JUNYUAN BAGS runs 4,950 m² of SGS-verified production floor across 7 lines with 149 machines, staffed by 137 people, giving a monthly capacity of 200,000 pieces. Those figures are stated because they can be checked on site, which is the only kind of capacity claim worth making.
For a buyer, the practical follow-up is to ask what portion of that capacity is available in the specific months you need, and to confirm it in writing with a delivery schedule rather than a brochure figure.
Check the number before you plan around it
Send the styles, volumes and delivery window. The programme team will confirm what is available in those months and put it in a delivery schedule rather than a brochure.
Frequently Asked Questions
How do I verify a supplier's claimed monthly capacity?
Reconcile the claim against inputs that scale with production: thread and hardware purchases, electricity consumption, production headcount and, most usefully, recent bills of lading. Then identify the bottleneck operation and calculate output from its cycle time.
What is a bottleneck operation in bag production?
The operation with the longest cycle time per unit, which sets the pace of the whole line. In bags it is often skiving, die cutting, edge painting or complex hardware setting rather than stitching.
Why is stitching rarely the constraint?
Because sewing machines are relatively cheap and numerous, so factories accumulate them. Skiving and edge finishing require skilled operators and fewer machines, which is where queues form.
What is line balance and why does it matter?
Line balance is how evenly work is distributed across operations. An unbalanced line has idle operators and accumulating WIP, and its real output can be half of what machine counts suggest.
Can capacity be available but not accessible to me?
Yes, and this is common. Capacity committed to anchor customers is not available capacity. Ask for the committed load percentage per line for the next three months, and for the last twelve months of output by month to see the seasonal shape.
What does first-pass yield tell me about capacity?
Whether the factory can produce at its claimed rate without rework. Rework consumes the same capacity as production, so a low first-pass yield reduces effective capacity below the nominal figure even when machine counts are unchanged.
Is subcontracting a red flag?
Not in itself — it is normal for specialised operations. Undisclosed subcontracting is the red flag, because it moves production outside the factory you audited and usually outside your inspection scope.
How many inspectors should a factory have?
Enough that inspection is a dedicated function rather than something operators do between tasks. Ask for the inspector headcount and for a sample of defect records; a factory with no defect data is not managing yield.
What documents should I ask for?
Output by month for the last twelve months, committed load for the next three, first-pass yield and rework rates, production headcount and attendance, and recent bills of lading. Photographs of WIP buffers at each station are a useful supplement.
How often should capacity be re-checked?
Annually, and before any significant volume increase. Capacity changes with equipment, headcount and the customer mix, and a figure from two years ago describes a factory that no longer exists.