Time links

Time links indicate the time sequence for linking two coupled batches or an end-product batch and an order. Time links are not applicable for decoupled batches. The two major time link constraints on a batch are the earliest start time and the latest end time.

• Earliest Start Time:

  For batches the earliest start time is the first point in time at which the batch can start, considering the time link of the batches coupled upstream. For end-product batches, the earliest start time of the orders is also considered. Coupled inflow batches that have an inline method move automatically with the batch. In this case, the earliest time is passed on to the downstream batch.

  For orders, the earliest start time is the first point in time at which end-product batches for this order can end.

• Latest End Time:

  The latest end time of a process batch is the latest point in time at which the batch can end and be ready for the following coupled batches. The Latest End functionality places the selected process batches on latest end time. For batches in an end product stage, latest end is order dependent. In coupled stages, latest end is determined by the outflow batches. Batches without a latest end and locked batches are not affected.

A batch must be scheduled to completely include within these constraints. Play is the difference between earliest start time and the start time or the difference between the latest end time and the end time, based on the higher limitation factor.

The same time links can also result in slack or waiting time for a tank batch.

If there is a multiple product flow, the most critical time link is used to determine the earliest start and latest end. Due date is a case in point.

For Inline methods, time links are not expressed in terms of play and slack. The upstream coupled batches adjust the outflow to the downstream batches.

You can view time links as arrows if you drag coupled batches in the planning board and the Signaling check box is selected.