Considerations for Calculating Lead Times

When you run the Calculate Lead Times and Roll Up Cumulative Lead Times scheduled process to calculate the manufacturing lead times, cumulative total lead times, and cumulative manufacturing lead times for certain items, there are a few validations that the application performs which you must consider:

Key Considerations for Lead Time Calculation

The following points are key considerations for lead time calculations in manufacturing:

• The application only considers the primary work definition with production priority of 1 of an item when calculating its lead times. The calculation is done considering whether the work method selected for production priority of 1 at each level is discrete manufacturing and process manufacturing.

• The item must be set up either as a make or a buy item in the Product Information Management work area.

• For any level in the item hierarchy, if a phantom item is encountered, then the application explodes it till no further lower-level phantoms can be exploded and the flattened list of component items are included as part of that particular level.

• While calculating, if any of the values aren't available because either you didn't specify or if the scheduled process was never run previously for the manufacturing lead times, the application treats the empty values as zero.

• If a same component is assigned more than once to different operations, the component is evaluated twice because it's consumed twice in two operations.

• The precision of the lead time values are displayed in the output text file based on the value set in the profile Time Duration Decimal Precision. The precision of the final lead time values stored in Item definition is based on the precision set in Oracle Product Information Management.

• For process manufacturing, manufacturing lead time calculation considers all operations of the primary work definition irrespective in which operation the output item is yielded.

• For process manufacturing, the manufacturing lead time of the primary product is copied over to the co-product or the by-product if:

  • the co-product or by-product is within the domain of items selected in the scheduled process

  • the co-product or by-product doesn't have a primary work definition of its own

  • the manufacturing lead time for the co-product or by-product wasn't calculated previously in the current scheduled process.

    Once the lead time of a co-product or by-product is computed, it's not overwritten by a subsequent calculation.

• For process manufacturing, the cumulative manufacturing lead time of the primary product is copied over to the co-product or the by-product if:

  • the co-product or by-product doesn't have a primary work definition of its own

  • the cumulative manufacturing lead time for the co-product or by-product wasn't calculated previously in the current scheduled process.

    Once the lead time of a co-product or by-product is computed, it's not overwritten by a subsequent calculation.

    For details about which factors impact lead time scheduling when calculating lead time duration, refer to the How Work Orders are Scheduled section in the Manage Production chapter.

• The manufacturing lead time calculation supports an adjustment when resources of the first operation don't start in the first shift of the plant. In such cases, the scheduled start time is different from the start time of the first shift. A correction factor computes the difference between the schedule start time and the first shift's start time. This correction factor adjusts the calculated manufacturing lead time to improve lead time accuracy in case of partial shift assignments.

• The manufacturing lead time calculation program always considers the plant calendar when calculating the lead times, even if the work definition includes work centers with override calendars.