**2.1 Definition of D (day) minus 1**

The production model D minus 1 is a production control cycle model that uses N process stages, the planning time horizon is the delivery time of ST (days), the processing time cycle is ST-N + 1 (days) and the process period is daily. Production activities in this case use three stages process, so processing time is ST-2 (days), see **Figure 2**.

The characteristics of this model are:

