Time fences form an integral part of the Inventory ATP Query program that is available throughout the system. They enable you to define rules for changes to forecasts and the acceptance of sales orders.
The following explains the use of working days and calendar days in the time fence calculations:
If the stock item is bought out, then the lead time is entered against the stock code.
The system has to assume absolute days in this case, as we have no control on whether the supplier works 24/7 or not.
If the item is made-in, then the lead time calculation program inflates the manufacturing lead time by the ratio of working to non-working days. This is to give a more accurate representation of the lead time for use in SYSPRO. This is because we are in control of the manufacturing time and it uses our factory calendar.
Because of the above, the lead time (and manufacturing lead time) are added as absolute days (i.e. non-working days are not taken into account on the factory calendar).
The Demand time fence (defined against each stock item which is defined as a Make to order), Frequency allowance (defined in Requirements Planning Setup), Dock to stock (defined against the stock item) and Planning horizon days (defined in Requirements Planning Setup) are all assumed to be entered as absolute days. However, because we are in control of these fields, non-working days defined on the factory calendar are taken into account when adding these on.
| Field | Description |
|---|---|
| CD - Current Date | This defaults to the system's run date. |
| DTF - Demand time fence |
This indicates the number of days required to tailor the part to order. This is calculated as: Demand Time Fence = Current date + Demand time fence days + Dock to Stock days All items defined as make-to-order will have the demand time fence printed. The period when the demand time fence is printed on the MPS is calculated by adding this field to the run date. |
| TTF - Transfer time fence |
This is calculated by adding any warehouse lead time for an item to the demand time fence. Non-working days are not taken into account when applying the Lead time (days) defined for transferring items between warehouses (Warehouse Maintenance for Stock Code) when the option Use absolute days when applying lead time to transfer supplied items is enabled (Inventory Setup). If no lead time has been set up against the stock code/warehouse, then the lead time is extracted from the Warehouse Move Matrix. If no lead time is defined in the matrix then lead time defaults to zero. |
| MTF - Manufacturing time fence |
This indicates the number of days that it takes to build an item, assuming that all the raw materials are available. This is calculated as: Manufacturing Time Fence = Current date + Manufacturing Lead Time This field can be entered manually, or calculated using the Lead Time Calculation program. The manufacturing lead time is added to the planning frequency allowance and dock-to-stock days to generate the manufacturing time fence. |
| PTF - Planning time fence |
This is calculated by adding the dock-to-stock, planning frequency allowance and the overall lead time (i.e. the longest lead time to make and purchase all the components that are required for a finished item). This is calculated as: Planning Time Fence = Current date + Lead time + Frequency Allowance + Dock to Stock |
| PH - Planning horizon |
This is calculated by adding the visibility factor to the planning time fence. Any date after the planning horizon is not normally subject to build schedules. The visibility factor is defined in Requirements Planning Setup. This is calculated as: Planning Horizon = Current date + Planning horizon days |
| Visibility factor |
This indicates the number of days from the planning time fence that general planning will take place. The visibility factor is defined in Requirements Planning Setup. |