Features

Elements of Scheduled Lead Times

When scheduling the operations for an order, four elements of lead time are used in the calculations:

·     Move:  the time taken to move components from an operation in one workcenter to the next operation in a different workcenter.

·     Queue:  the time taken to move components from one operation to the next in the same workcenter.

·     Setup:  the time to prepare an operation.

·     Run:  the actual elapsed run time for an operation.

The move and queue times are a buffer between consecutive operations.  Move and queue times are mutually exclusive; they are applied as an offset before the start date of the next operation is calculated.

Overlapping Operations

The system allows for an operation to begin its run time prior to the completion of the preceding operation.  Overlap may be defined in one of two ways:

·     Overlap Quantity:  the number of parts that must have been completed at the preceding operation before the following operation can begin.

·     Overlap Percent:  the percentage of the order quantity that must have been completed at the preceding operation before the following operation can begin.

For both definitions of overlap, move and queue times are applied before the subsequent operation begins.

Operation Types

The operation type is defined for each operation in the Manufacturing Engineering module; this determines the method by which the operation is scheduled, and by which start and due dates are assigned.  Each operation type has specific requirements for the various elements of the lead time defined above.  The definitions and requirements of each operation type are summarized in Exhibit C found in the Lead Time Calculations key concept.  An illustration of how successive operations are scheduled for each operation type is provided in Exhibits D through G found in the Lead Time Calculations key concept.

·     Operation Type 1 - Standard.  This operation type requires all components to be available from the preceding operation before setup can commence.

·     Operation Type 2 - Master Operation.  This type of operation is not itself scheduled.  Master operations are used to summarize two or more detail records for reporting purposes only.  The start and due dates are determined by scheduling all details associated with the master.

·     Operation Type 3 - Setup Only Overlap.  This denotes an operation that does not require any components to be available for setup of the operation.  However, all components must be available before the run can begin.

·     Operation Type 4 - Run Time Overlap.   This operation type is an overlapping operation that may commence the run prior to completion of the preceding operation; components from the preceding operation are not required for setup.  The user specifies the quantity or percentage of the order quantity that must be available from the previous operation before the run can commence.

·     Operation Type 5 - Setup and Run Time Overlap.  This requires some but not all components from the preceding operation before commencing setup and run.  As long as the overlap quantity/overlap percent requirement is met, both setup and run time may overlap.  The user specifies the quantity or percentage of the order quantity that must be available from the preceding operation before setup and run can begin.

·     Operation Types 6 and 7 - Fixed Time Operations.  The run time for these types of operations is considered to be independent of the order quantity.  The system assumes that the entire order quantity must be available prior to starting the operation, and that the entire order quantity is available when the fixed time operation ends.  Move or queue time can be associated with both types of operations.  The difference between the two is that type 6 operations require the components from the previous operation prior to commencing setup.  For type 7 operations, setup is assumed to be independent of receiving components from the prior operation.

Outside Processed Operations

Outside processed operations do not have operation types or the elements of scheduled lead time associated with them.  The "lead time" is defined on the routing record in number of days.  As with fixed time operations, the total order quantity is assumed to be available at the start of the operation, to be required for the duration of the operation, and to be totally available when the operation is complete.