The production lines for drawers and folders could not be takt because of the significant differences in routing time from one reference to another. They could not be piloted in Kanban either, because the number of article codes manufactured is too high.
The CONWIP (CONstant Work In Process) method was chosen as the pull flow method adapted to the demanding context of the sector.
In concrete terms, these are pockets containing the manufacturing files that serve as Conwip tickets. These folders are stored in boxes that represent the different stages of the routing paths. The workers remove the folder from the box, perform the operation and transfer the folder to the box of the next operation.
The nominal in-process level at each stage has been calibrated with the WipSim simulator. Thus, the appearance of a floating bottleneck is immediately detected.
The control of the total number of boxes in circulation makes it possible to control the total work-in-progress, and thus to limit the crossing time. The state of health of the line and its possible points of accumulation are visible permanently by all.