Inside a Kit Assembly Line

A modern kit assembly line is a straight-through progression from panel-bundle intake at one end to folded-garment output at the other. Operators sit in a fixed order, each with a dedicated machine and a small feeder table beside them.

1. Bundle intake — pre-sorted, size-matched panel bundles delivered from cutting.
2. Station 1: Shoulder join with tape reinforcement (4-thread overlock).
3. Station 2: Neck rib preparation — rib cut, ends closed on lockstitch.
4. Station 3: Neck attach + topstitch (overlock + coverstitch, sometimes split into two).
5. Station 4: Sleeve preparation — sleeve hem on coverstitch.
6. Station 5: Sleeve set into armhole (overlock).
7. Station 6: Side seam close from hem to sleeve cuff (overlock or flatlock).
8. Station 7: Body hem (coverstitch).
9. Station 8: Trim, thread-clip and inspect.
10. Stations 9–12: Decoration — heat-transfer numbers, badges, neck label.
11. End station: Fold, polybag, hangtag, carton.

Takt time is the pace at which the line has to produce a unit to hit the daily target. For a 500-kit day on a 480-minute shift (8 hours minus breaks), takt is 480 × 60 / 500 = 57.6 seconds per garment. Every station must complete its operation inside that window or the line stalls.

Sleeve set is the classic bottleneck on a jersey line. Two mitigations: split the operation into 'sleeve-cap prep' and 'sleeve-cap set' across two stations, or move the fastest operator (hem station in the example above) into a support role.

Between every two stations sits a small table with garments in progress. This is WIP — the shock absorber for the line. Get it wrong and the line either starves or drowns.

• Too low (<5 min buffer) — one operator's needle change stalls three downstream stations.
• Too high (>20 min buffer) — a defect at station 2 makes it to station 8 before anyone notices, so 40 pieces need rework.
• Target — 8–12 minutes of buffer between stations. Enough to absorb hiccups, small enough to catch defects quickly.

Quality is not an end-of-line inspection. It is a series of checks at every station:

• Operator self-check — first 3 pieces of every hour measured against the tech pack.
• Roving QC — a floor auditor pulls 1 in 20 pieces and grades against defect codes.
• Bundle end audit — after the last sewing station, every bundle sits under a strong lamp for visual inspection.
• Rework loop — defects tagged and sent back to the responsible station, not passed forward.

500 sewn kits per shift is the plateau where a well-run 12-operator line settles. To exceed it you either add a parallel line, add a 2nd shift, or accept a garment-complexity downgrade (fewer panels, no side seams, no engineered graphics). Below 350 kits is a sign of a balancing problem, not a labour problem — walk the line and find the bottleneck station.