A novel optimization model for sequencing automobile assembly shops

To solve the sequencing problem in automobile assembly shops, the colour batch size constraints of paint shop and the spacing constraints of the assembly shop are explicitly discussed. The spacing constraints are proved to be a sufficient condition for the capacity constraints. On the basis of those, the spacing constraint inequalities with utility workers are presented. An integer programming model is presented where the cost of utility workers and the cost of setups are to be optimized simultaneously. For computing conveniently, some nonlinear constraints in the model are transformed into linear constraints. Simulation results confirm the feasibility and validity of this proposed method.