"Bundling" is the process of disassembling the stacked and cut pieces and reassembling them in production lots grouped by garment unit, colour dye lot, and number of garments. Manufacturers use a variety of bundling methods depending upon their needs, with four basic systems being the most common among local manufacturers:
- Item bundling - all pieces that comprise a garment are bundled together.
- Group bundling - several (10-20) garments are put together in a bundle and given to a single operator or team to sew.
- Progressive bundling - pieces corresponding to specific sections of the garment (such as sleeves or a collar) are bundled together and given to one operator. Other operators sew other parts of the garment, which are then assembled into the finished garment in the final phase.
- Unit production system (UPS) - individual garment pieces are delivered to sewers using a computerized, fully mechanized "assembly line" that runs throughout the manufacturing facility. Using a UPS computer monitoring system, a manufacturer can fully track the production of a garment, identify where sewing slowdowns are occurring, and reroute garment pieces to other sewers who work more quickly. Gerber Garment Technology Inc. manufactures a UPS system, which eliminates the need for passing apparel piece bundles from worker to worker. This lowers labour costs because employees spend less time handling bundles and more time sewing. It also facilitates short-cycle manufacturing.
- Modular or "team based" manufacturing is another type of bundling that combines some of the above characteristics. Developed in Japan, it is the grouping of sewing operators into teams of eight to ten. Rather than each sewer performing a single task, they work together on a garment from start to finish. One-third of the U.S. apparel industry has switched to either unit production or modular manufacturing. In Los Angeles, however, only a few major manufacturers engage in computerized unit productions (constituting about ten percent of total production) while the majority of contractors still use progressive bundling.
Bundling workers also carry out important quality control functions. They inspect the garment pieces for cutting problems, fabric irregularities, or any other problems that may have occurred in production thus far.