About Time Links

Earliest Start Time

• For batches (select a batch and then Schedule > Earliest start), it is the first point in time at which the batch can start, taking into account the time link of the batches coupled upstream. For end product batches, the earliest start time of the orders is also taken into account. 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, it is the first point in time at which end product batches for this order may end.

Latest End Time (determined by a subsequent or downstream batch)

The latest end time of a process batch (select a process batches and then select Schedule > Latest end) is the latest point in time at which the batch can end so that it will still be ready for the following coupled batches. The function latest end places selected process batches on their 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 so that it falls completely 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, depending on which is most limiting:

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 their outflow to the downstream batches.

You will see time links as arrows if you drag coupled batches in the planning board and if the Signaling option is checked.