Safety Time/Actual Range of Coverage
The safety time / actual range of coverage ensures that the planned warehouse stock covers the requirements of a defined number of days. It therefore serves as a time float and thus works alongside the safety stock, which acts as quantity float.
The system simulates bringing the requirements forward by the specified number of days and the planning for the receipts, created for these requirements in the planning run, is also brought forward by this number of days.
· You have set the Safety Time indicator in the material master record (MRP 2 View) to define whether the safety time is only to apply to independent requirements or to all requirements.
· In the material master record (MRP 2 View), in the Safety Time/Actual Range of Coverage field, you have entered the number of workdays by which the requirements are to be brought forward.
· If, in addition to this actual range of coverage, you also want to define a different number of workdays in certain periods or a safety time less than one day then, in Customizing for MRP in the activity Define Period Profile for Safety Time/Actual Range of Coverage you can define a period profile and assign it to the material in the material master record.
You also access this Customizing activity from the SAP Menu by starting from the MRP node and choosing Environment →Current Settings →Define Period Profile for Safety Time/Actual Range of Coverage. You do not need any customizing authorization to maintain such a profile.
Safety Time/Actual Range of Coverage
The requirements are brought forward on the time axis by the number of days you defined in the material master record.
The work scheduler defines a safety time / actual range of coverage of 2 days. A requirement exists for January 31st. In the planning run, the system brings the requirements date forward by 2 days in simulative mode and creates a planned order with the end date on January 29th. However, the actual requirements date (January 31st) does not change.
The disadvantage of this procedure is that a procurement element is created for each requirement. The system only groups the procurement quantities for the requirements into one procurement element if you work with weekly lot sizes or monthly lot sizes.
Safety Time / Actual Range of Coverage for Time-Phased Materials Planning
Time-phased materials planning is based on the interval between the MRP date and the availability date of the next MRP date. If you use the actual range of coverage, the system adds the number of days of the actual range of coverage to this availability date. Time-phased materials planning is then carried out for the changed period.
Period Profile for Safety Time / Actual Range of Coverage
· Defining an alternative actual range of coverage for certain periods
In certain periods, it may be necessary for you to plan using a different actual range of coverage from the one defined in the material master. To smooth out seasonal fluctuations, you can use the period profile for any definable period of time to define an alternative actual range of coverage from the one defined in the material master record. This means, for example, that you can define a higher range of coverage than normal in the period profile for the months leading up to Christmas to cope with increased demand.
In the planning run, the system checks whether you have assigned a period profile to the material and whether the requirements date falls in one of the periods defined in the profile. If yes, the system uses the actual range of coverage from the period profile. If not, the system uses the actual range of coverage from the material master.
· Defining a safety time of less than one day
You can also use the period profile to define a sub-day safety time for certain periods. You do this by entering a percentage value in the Safety Time % field as well as the safety time. The system then splits the daily requirements according to this percentage and moves these partial quantities another day forward on the time axis.
If you want to define a safety time of 2.2 days, enter 2 (days) in the Safety Time field and 20 (percent) in the Safety Time % field. The system then splits a daily requirement of 100 pieces with the requirements date 09.09.2004 as follows:
Earlier Reqmts Date Quantity
09.06.04 20 pieces
09.07.04 80 pieces
In the planning run, the system creates the receipt elements according to the earlier requirements dates.
You can display the requirements dates that have been moved forward in simulation by selecting the function key Switch On Safety Time in the stock/requirements list. The System then shows the earlier, calculated requirements date instead of the actual requirements date. See also: Working with the Single-Row Display
If you use a sub-day safety time in the period profile, the split requirement quantities are always displayed as the system splits the quantities according to the defined percentage value. Both quantities are displayed on the same requirements date if you have switched off the safety time display. When you switch on the safety time, the system displays the earlier dates as shown in the example above.