About job scheduling options
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About job scheduling options

Dynamics AX 4.0

Job scheduling is the control of your manufacturing environment by scheduling individual jobs (or shop orders).

Job scheduling allows the synchronization of the production order's other jobs and any references associated with the current job. You can specify a starting or finishing date and time for the job, and then run scheduling on that basis. Whether the time you specify is a starting or finishing time depends on the choice of scheduling direction. This is useful if a given job can be run only on one machine at a certain time, or in connection with optimization of the job run for each of the work centers.

For more information, see Dispatching (Form).

  • Apply the Forward from scheduling method to begin the production as early as possible. This is also known as the push method, because the production is being pushed through the production process as quickly as possible. The production is scheduled to start at the earliest date possible and is planned forward in time to the earliest possible end date.

  • Apply the Backward from scheduling method to begin the production as late as possible. This is also known as the pull method, because it is based on the date that the production must be completed and counts backward to the latest possible date that the production can be started without missing its target deadline.

Job scheduling allows scheduling with limited capacity. When limited capacity is applied, job scheduling takes into account that the capacity scheduled cannot be greater than the capacity available for the work center. Available time is defined as the time interval where the work center is open, and where there are no other reservations on capacity.

Scheduling with limited capacity ensures that there is no overlap in an operation's starting and ending times on a specific date. The capacity already reserved on the work center is taken into account, and overlaps between starting and ending times are considered. Limited capacity determines the amount of capacity that has to be available for the work center for optimal use, balanced with calculating the shortest possible lead time between operations.

Job scheduling with limited materials ensures that the required materials are available when the operation begins. The general coverage rules set these limits, because scheduling uses a requirement explosion to establish when the component items are available. If you schedule without setting limited materials, the system will assume that all items are available when needed.

Job scheduling with limited properties requires that properties be specified for the production route's operations. These properties must be fulfilled in order to reserve capacity.

For more information, see Properties (Form).

Job scheduling schedules all reference productions associated with the current production. If a production has one or more subproductions, they should be scheduled with the main production, because the main production cannot be launched until the related subproductions are finished.

In job scheduling, efficiency percentages specified for the work centers are also used. Efficiency percentages are set up on the work center.

Efficiency percentages reduce or increase the time reserved for the work center. Consequently, lead time is also increased or decreased. The rule for the calculation is: Scheduling time = Time * 100/Efficiency percentage (where time is the run and setup time).

Job scheduling examines all possible work center combinations with a task group, and then chooses the work center with the shortest lead time. As a result, performance may be reduced. This can be a concern when there are many resources in the same work center group, and secondary operations are used. A maximum of 32 work centers can be scheduled per operation. Extending this quantity results in an Infolog entry, and the job scheduling will not find the best alternative work center.

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