Optimally Loading Clocked TowTrains for JIT-Supply ofMixed-Model Assembly Lines

In today's mixed-model assembly production, there are two recent trendsin particular, namely increasing vertical integration and the proliferation ofproduct variety, which more and more shift focus to an ecient just-in-timepart supply. In this context, many automobile manufacturers set up decen-tralized logistics areas referred to as supermarkets. Here, small tow trainsare loaded with parts and travel across the shop oor on specic routes tomake frequent small-lot deliveries which are needed by the stations of the line.This paper investigates the loading problem of clocked tow trains, which aimsat minimizing inventory near the line while avoiding material shortages giventhe limited capacity of tow trains. An exact solution procedure with polyno-mial runtime is presented and interdependencies with production planning,i.e., the sequencing problem of product models launched down the line, areinvestigated...