The conveyance system moves parts between stations in an assembly line. It should not be a WIP buffer, it should not artificially separate subsequent stations, it should not lose product orientation, and it should not be shared among multiple conveyance tasks. The goals for the conveyance system include, for quality reasons, preserving the process sequence by moving one unit at a time in first-in-first-out mode and by being unobtrusive, safe, and inexpensive.

Products that are small and light can simply be passed between operators' hands. If syn-chronization is too difficult, a one-piece buffer between stations is appropriate, but WIP accumulation beyond one unit should be prevented. For heavier products in low volume, pushcarts with a fixture on top can be used both as rolling assembly stations and for conveyance. For large products, these carts can also be scissorlifts on which the product can be lowered progressively through the assembly process to maintain a constant work height. Such systems do not enforce the takt time, and must therefore be supplemented by production pace monitors. Powered conveyors, on the other hand, can be used to enforce takt time. Continuously moving conveyors allow assembly to proceed during the entire takt time, but require assemblers to work on a moving object. Stop/start conveyors, on the other hand, allow the assemblers to work on a fixed object but lose time for transfers between stations. Very long workpieces can be placed on a truck flatbed and pulled forward slowly by a winch. This presents different sections...