Scheduling Collective Orders
Use
If a production order contains a component that is manufactured using a second production order (direct production),the requirements date for this component serves as the order finish date for the second order. If the second production order again contains a component that is manufactured using a third production order, the requirements date for this component serves once again as the order finish date for the third order, and so on.
When you are scheduling a subtree or a complete collective order, you enter framework dates in the order that is on the top level. These framework dates serve as a guideline. They mark out the period within which the system tries to schedule the current order and all the subordinate orders.
Collective orders are normally scheduled backwards . Therefore, if you have entered an framework finish date in the top order of a collective order, the system goes backwards from this date and schedules each order backwards, starting with the requirements date for the component, that is produced in the order. The order start date for the earliest production order is identical to the framework start date for the collective order.
The following graphic contains an example of backwards scheduling in the collective order (without Taking Into Account Move Time ):
Features
Dates Proposed Manually in a Collective Order
Framework dates serve as guidelines for scheduling the collective order: When scheduling a subtree or a complete collective order, you must propose at least one framework date according to the scheduling type:
Framework finish date
The system tries to complete the current order and all dependent orders before this date.
Framework finish date
The system schedules the current order and all dependent orders after this date.
Framework start and finish date
The system tries to schedule the current order and all dependent orders within the specified time period. On scheduling, if it is established that the framework dates cannot be kept to, then the system uses reduction measures to try to shorten the lead time of the scheduled orders.
If an order’s start date is in the past, the system switches to Today Scheduling . In this case, you receive an appropriate warning message in the scheduling log.
Note
You can propose framework dates on various levels in a collective order. Note, however, that every proposal of a framework date represents a fixed schedule for the corresponding sub-tree. This may lead to the situation in which the dates of individual orders in the collective order are no longer coordinated.
Calculated Dates in a Collective Order
Collective order scheduling calculates the dates for the individual orders (basic dates and scheduled dates) and the scheduled dates for the collective order.
The result of lead time scheduling has the following effect on the collective order dates:
The earliest order start date of all orders represents the scheduled start of the collective order
The latest order finish date of all orders represents the scheduled finish date of the collective order
If the framework dates could not be kept to, then the scheduled dates and the framework dates in the collective order are different. In this case, you receive an appropriate warning message in the scheduling log.
Scheduling Individual Orders in a Collective Order
When you schedule an individual order, proceed as for scheduling a normal production order.
Scheduling Subtrees or Whole Collective Orders
When you schedule more than one order at the same time
Scheduling can only be executed if you access the sub-tree or the entire collective order
Framework dates that were entered at a lower level are taken into account during the scheduling run
The user has to enter at least one framework date:
The system tries to keep to all existing framework dates that were entered on a lower level.
Note
Framework dates are only then written to an order, if they are entered manually.
The basic dates for all orders in the subtree / collective order to be scheduled are brought into line with the scheduled dates.
Forward scheduling allows both basic dates to differ from the framework dates.
With backward scheduling, the order finish date should be the same as the framework date.
Note
If an order deadline that is determined in a scheduling run comes after the requirements date for the components to be produced, the scheduling log informs the user about it. If the user saves the orders despite this warning, then a system status is set in the corresponding order.