Abstract
Instead of conventional constant speed assembly lines, complex free flow assembly lines are sometimes utilized to assemble many product variants in automobile and other industries. In such assembly lines, a job is transferred to the next stage when the transfer is permissible and the next stage is vacant. Two types of buffers, series and parallel, are used along the line. A series buffer can be considered as a stage with a zero processing time. With a parallel buffer, some work can be postponed, i.e., the production sequence can be changed after the parallel buffer. In this paper, we will formulate a production sequencing problem explicitly for a complex free flow assembly line with bypass stages as well as parallel buffers. We validate the formulation by solving some examples using mathematical software. This formulation will be useful to evaluate the objective function value more efficiently than executing a simulation in meta-heuristic algorithms, although the way how to evaluate the objective value using the formulation is not discussed in the paper.
