Parallel Sequences
Use
A sequence groups together operations in the order. Operations in a sequence are processed according to their place in the sequence. Sequences are linked in network-like structures. Sequences are defined in the routing and transferred to the production order when it is created.
A parallel sequence is a sequence that runs parallel to operations in the standard sequence. The start of the parallel sequence corresponds to the start of the branch operation in the standard sequence. The end of the parallel sequence corresponds to the end of the return operation.
If several sequences run parallel in an order, the execution times are usually of varying lengths. As a result of this, time floats develop in the sequences. These floats may exist both at the start and at the end of the sequence. The alignment key of the sequence controls where a possible time float is situated in a sequence: If the sequence is aligned
with the earliest date, the float is placed at the end of the sequence
with the latest date, the float is placed at the beginning of the sequence
The alignment key is assigned to the standard sequence and to each of the parallel sequences in the routing.
The following diagram shows the connection between the alignment key and the chronological alignment of the sequences. While the three parallel sequences are aligned to the earliest possible date, the standard sequence has an alignment key that plans according to the latest allowed alignment.
Note
Alternative sequences are only taken into account during scheduling when they have been exchanged with the standard sequence during the creation or change of a production order.