Heijunka Mixed Model Sequencing Problem with no Buffers and Work Overload Minimization

A sequence problem is presented in production lines of mixed fixed-cycle models and time windows with the aim of minimizing production losses in the line and taking into account two types of restrictions: leveling of Heijunka production and suppression of buffers between workstations. The proposed problem is solved by mixed integer linear programming (MILP) using the IBM-CPLEX solver on the set of 23 Nissan-9Eng.I instances. It is concluded that the economic impact due to incremental production losses is significant when the buffers are suppressed in the production line, being of the order of €2600/day.