Understand the default latest start times for operations

The default latest start times for operations are determined by the system based on the following properties:

• The item quantities to be produced by each operation in the process

• Estimated production rate (including batch size) for each operation in the process

• The percentage of produced items coming to each operation that are required to allow that operation to start

• The work order's required finish time

The latest start time for each operation in a process is based on the slowest path through the downstream operations in the process.

The following examples demonstrate how the earliest start times are determined.

Process with no parallel operations

The following diagram shows the latest start and finish times for a process with the following characteristics:

• The process has no parallel operations

• The estimated production rate for each operation is 120 pieces per hour

• The production for the work order must be completed by 11:00

• Each operation requires that 100% of the starting quantity coming from the previous operations be available to start that operation

  

Process with parallel operations, all requiring 100% item quantity to start

The following diagram shows the latest start and finish times for a process with the following characteristics:

• The process has parallel operations, with the parallel operations producing different percentages of the total item quantities

• The estimated production rate for each operation is 120 pieces per hour

• The production for the work order must be completed by 11:00

• Each operation requires that 100% of the starting quantity coming from the previous operations be available to start that operation

  

Process with parallel operations, final operation only requiring 70% item quantity to start

The following diagram shows the latest start and finish times for a process with the following characteristics:

• The process has parallel operations, with the parallel operations producing different percentages of the total item quantities

• The estimated production rate for each operation is 120 pieces per hour

• The production for the work order must be completed by 11:00

• Each operation except that last one requires that 100% of the starting quantity coming from the previous operations be available to start that operation; Operation 5 requires only 70% to start.

  

Note that, because Operation 5 can be started with only 70% of the starting quantity being available, the latest start time for Operation 4 is based on producing 70% of the entire quantity instead of the entire 100%. Therefore, the latest start times for Operations 1 through 4 are later than for the previous example. That is, in the previous example, the first operation would have to start sooner to meet the work order's required finish time.