Freeze Schedule

 

The DMS Scheduler has a “freeze” option that enables you to freeze operations that are scheduled out x number of days from the last schedule run.  For example, if you selected to freeze the schedule out 5 days from the last schedule run, the Scheduler will select all the operations out 5 days from the last schedule run date and try and load the entire job's operations on their scheduled day and shift. 

 

Freeze Schedule has two options:

1.Freeze schedule from last schedule start date x days  Enter the number of days out from the last schedule run from which you want to freeze operations.  This option can also be changed for each schedule run on the Schedule Run tab.

2.Freeze schedule suppress warnings  If this option is selected, warning messages informing you that one or more frozen operations could not be scheduled on their previous start date or start shift will not be written to the status report.  If unchecked, warning messages will appear.  This option can also be changed for each schedule run on the Schedule Run tab.

 

The following rules apply to freezing the scheduled operations:

1.Selection of frozen operations is performed by priority plus due date.

2.Operations that have been completed since the last schedule run are ignored.

3.If the date of a frozen operation is in the past, the operation will be loaded on the first day available.  That is, if a frozen operation was schedule to start yesterday it will be scheduled on the first available day in the new schedule run. 

4.Frozen operations can be loaded before or after started/locked operations as selected in the Schedule options.  It is recommended that you test which method works best for your environment and then set the option as a policy.  In most circumstances you will want to load frozen operations after schedule started/locked operations.  Therefore, the option to load frozen operations before started/locked operations should not be selected.

5.If a job contains a frozen operation, the entire job and its operations are scheduled using the operations' current schedule start and end times.

6.If an assembly contains a job that has frozen operations, the entire assembly is scheduled using the operations' current schedule start and end times.

7.The scheduler cannot guaranty that frozen operations will be scheduled on the same date and shift as in a previous schedule run as:

1.In-process work, editing operation runtime changes, material delays, manually locked operations, etc. may push out frozen operations.

2.Manual date changes to frozen operations by the schedule board or other method may overload a resource and thus be pushed out.

3.Capacity changes and holidays may change available resource capacity.

In summary, the scheduler will try and load the frozen operations on the same day and shift but the dynamics of scheduling may move frozen operations to a different day and/or shift.