how is Forecast error in Product master calculated

[Former Member]

Dear gurus,

Kindly help me in understanding how the 'Demand forecast err%' field in Product master 'Lot size view' is calculated. In our case, the value is always 0% even for products which has historical data. The safety stock method we use is BT.

Is there a program to be run separately to calculate this field?

Thanks

Vignesh M

[Former Member]

Hi Vignesh,

Now, u can also enter the demand forecast error directly in this field( in product master). It is recommended that u enter the information directly in the following instances:

a) If the product is new with no or very little historical data available which is not significant for calculation.

b)If the forecast error is considered to be constant.

U can specify values of between 0.0% and 999.9%. If the value is 0.0%, the system uses historical data to determine the relative forecast error of the demand. If you do not enter a value, the system assumes that the forecast error is 0.0%.

If you enter a value larger than 0.0%, safety stock planning in SNP uses this value as a relative forecast error of the demand. The system does not evaluate historical data in this instance.

As u r using BT as safety stock method, the system calculation is as follows: "The expected fulfilled demand is divided by the expected total demand". As per ur historical data the system will calculate as per the rule previously mentioned.

And u dont need to run any program separately,the system only takes into account the value specified in this field if you have chosen one of the extended safety stock methods (AS, AT, BS, or BT) from the Safety Stock Method field.

Hope ur query is cleared.

Regards

Kishore Reddy

[Former Member]

Hi Kishore,

Thanks for your response. Yes, the details given by you are as per the details of SAP library. However in our case, we do not want the error to be manually entered. We need the system to calculate automatically. Hence we leave it as 0.0%. But we have never observed system calculating it automatically for the products with historical data.

Any idea on this? Please guide me the settings that I needs to check for the automatic updation...

Thanks

Vignesh M

[Former Member]

Hi Vignesh,

You need to maintain SFT Planning profile and use that planning profile in the safety stock planning (/SAPAPO/MSDP_SB).

In SFT profile maintain demand forecast error % as 100 then it will calculate based on the History.

If you want the system should take the 80% of history demand forecast error % then maintain as 80%.

Regards,

Kishore Reddy.

[Former Member]

Hi Vignesh,

In ASSP system calculates the demand forecast err%, Service Level % and RLT Fcast Error% calculate by the system dynamically based on the history.

If you maintain these fields then system consider the maintained data in safety stock planning.

Hope this clarifies.

Regards,

kishore Reddy.