In certain planning situations, the system may use lead time to approximate the time needed to acquire, make, or receive an item. In all cases, lead time is defined in the following fields on the Items or Multi-Site Items form:
NOTE: Paper Work Lead Time and Dock-to-Stock Lead Time are also used by the MPS Processor, Material Planner Workbench Generation, and on the Order Action Report.
This help topic describes how lead time applies to purchased items, manufactured items, and transferred items. It also describes how to use the Expedited Lead Time functionality.
For purchased items, you must enter the lead time values manually in the lead time fields. The system uses purchased item lead time to perform the following functions:
For manufactured items, you can enter the lead times manually or use the Lead Time Processor to generate the lead times from the current routing's operation times. The system uses lead time to plan manufactured items in these situations.
NOTE: For manufactured items that are not specified as MRP Items, lead time is not used when the system passes parent item requirements down to components. Component due dates are based on the start date of the operation where the component is used (or the start date of the job, depending on the setting of the Plan Materials at Operation Start planning parameter).
The system uses lead time to plan transfer orders if:
The system calculates lead time for transferred items in the same manner as purchased and manufactured items, except it adds the transit time (defined on Inter-Site Parameters) to the total lead time. For example, if an item's lead time from the FLT + (VLT * Qty) calculation is 1 day, and it takes 3 days to ship to the receiving site, the total lead time is 4 days.
APS calculates the Release Date during the Planning run, using Current Operation times and any constraints caused by material or shift capacity (either infinite or finite). The following formula is used:
Start/Release Date = PLN Due Date - (FLT + DSLT + PWLT + (VLT * Quantity Required))
where:
FLT = Fixed Lead Time
VLT = Variable (per-piece) Lead Time
DSLT = Dock-to-Stock Lead Time
PWLT = Paperwork Lead Time
EXAMPLE: For this example purchase order, assume the following conditions:
The system calculates the release date of the purchase order by performing this calculation:
The lead time values expressed in days on system forms are converted to hours during these calculations.
For all calculations involving lead time, the system assumes a 24-hour day X 7-day week by default. If you are using APS, you can configure it to use a defined range of business days by creating a shift named PCAL on the Scheduling Shifts form. See Using Lead Time Shifts for more information.
For special cases where you need to reduce the normal lead time, you can use the expedited lead time features. APS uses expedited lead time when the initial pull planning using standard lead time projects a date in the past. You can apply lead time reduction for specific items or apply it to all items.
NOTE: When you use mass cross-referencing through the Material Planner Workbench Generation form, expedited lead time is not used.
The Use Expedited Lead Time parameter on the Planning Parameters form enables or disables the application of expedited lead times at the item level and global lead time reduction. You can enable or disable expedited lead time usage for runs of APS Planning (select For Planning) and/or for Get ATP/CTP operations (select For ATP/CTP).
If you specify a value for the Expedited Fixed Lead Time or Expedited Variable Lead Time values on an item, the lead time calculations use the expedited values INSTEAD of the item's normal Fixed Lead Time and Variable Lead Time values. For example, if Expedited Fixed Lead Time contains a value, the lead time calculation would be:
Start/Release Date = Due Date - EFLT + (VLT * Quantity)
NOTE: Expedited lead time applies to all receipts of the specified item. To specify early receipt of a single item for a single demand, use the Expected Receipts APS form. When analyzing "what if" planning scenarios, use the What If Expected Receipts form.
You can also reduce lead time for all items using the Fixed and Variable Lead Time Reduction parameters on the Planning Parameters form. These options reduce the standard fixed and/or variable lead time by the specified value for all items.
During planning, the system calculates the total lead time with this formula:
Start/Release Date = Due Date - (FLT - FLTR) + ([VLT - VLTR] * Quantity)
where:
EFLT = Expedited Fixed Lead Time
FLTR = Fixed Lead Time Reduction
EFLT = Expedited Variable (per-piece) Lead Time
VLTR = Variable Lead Time Reduction
Depending on the combination of selected options and values, there may be other combinations of the lead time formula, such as:
Start/Release Date = Due Date - (FLT - FLTR) + (VLTR * Quantity)
or
Start/Release Date = Due Date - EFLT + ([VLT - VLTR] * Quantity)
Notice that the Fixed/Variable Lead Time Reduction values reduce the standard lead times, while the Expedited Fixed/Variable Lead Time values specified on the Items form actually replace the standard lead times.
On the Purchase Order Lines, Purchase Order Blanket Releases, and Purchase Order Requisitions Lines forms, the Expedited field indicates when the system used expedited lead time to plan a line item.
On the Purchase Order Report, Change Order Report, PO Requisition Report, and the Change Order Detail Report, a note indicates when the system used expedited lead time to plan a line item.
On the Planning Detail form, Exceptions Report, or Material Planner Workbench form, the "Used Expedited Lead Time" exception message appears for a supply record if the system used expedited lead time to allocate that supply to a demand.
Your vendors may have temporary problems meeting their lead times for certain items. To ensure that APS creates the planned order for a purchased item with the appropriate lead time in this situation, enter the Earliest Planned Purchase Receipt date on the Items form.
This date temporarily overrides the item's standard and expedited lead times. When APS creates a planned order for this item, it determines that the item can be received either by the current date + lead time or by this Earliest Planned Purchase Receipt date, whichever is later.