Cumulative Lead Time

The Part Master File record for each part also contains a Cumulative Lead Time field.  The cumulative lead time is the number of days it  takes to deliver the item from when work is begun on its lowest level component.  You can enter the cumulative lead time for the part, or you can have MAC-PAC calculate the cumulative lead time from the other lead time information stored in the system.  If you have MAC-PAC calculate the cumulative lead times, the calculated lead times will override any cumulative lead time you have already entered in the field.  (The Cumulative Lead Time Report, DE580, will also be produced, listing both "before" and "after" values for the field.)  If you want to override the cumulative lead time calculated by the system, you can access the Planning screen in the Part Master Maintenance conversation and type a new value in the Cumulative Lead Time field.

Please note that Cumulative Lead Time field has no effect on system processing.  MAC-PAC schedules production using time-phased orders within each level of the item's product structure.  This logic uses the other lead time fields (setup time, run time per piece, move time, and fixed lead time) to schedule production (or purchase orders or transfer orders).so that all components are available when they are needed to meet the master production schedule.

To request that cumulative lead times be calculated, you use the Cumulative Lead Time Generation conversation (DE350E).  Lead times must be calculated for all parts within a plant, and only one request per plant is allowed at one time.  The request for each plant is stored on Reference File category K11.  Once the request is entered, you can modify it by re-accessing the Cumulative Lead Time Generation conversation and either deleting or changing the request. 

The following formulas are used to calculate cumulative lead times:

·     For planning, reference, non-stocked, non-standard, and bundle parts, no calculations are performed.

·     For purchased, raw material, and transfer parts:

-     If the part's lead time is fixed, then the Cumulative Lead Time equals the Fixed Lead Time Days.

-     If the part's lead time is variable, then
Cumulative Lead Time = (Run Units  times  Average Order Quantity)
                              plus Fixed Lead Time Days 
                              plus  Setup Days 
                              plus Transit Days

·     For manufactured and build-thru parts:

Cumulative Lead Time = (Run Units  times  Average Order Quantity)
                                    plus Fixed Lead Time Days 
                                    plus  Setup Days 
                                    plus Transit Days
                                    plus Longest cumulative lead time for any component.