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Automatic Reorder Point (MRP Type: V2 or VM) Planning – Part 2
Note: Automatic Reorder Point (MRP Type: V2 or VM) Planning – Part 1: Automatic Reorder Point – Part 1
Carry out Automatic reorder point and calculation of it:
Below is how automatic reorder point planning is carried out for single material using material master change (t-code: MM02)
MRP 1 View
Note: Validate that Reorder Point is blank.
MRP 2 View
Forecasting View
Note: Forecasting model, I am keeping J – Automatic model selection and Initialization: X – Initialization by system
Consumption Data Update
Execute Forecast
Forecast: Model Selection
Calculation of MAD, Error Total, Safety Stock, Reorder Point
Forecast: Parameters for Automatic Model Selection
Safety Stock Update on MRP 2 View
Reorder Point Update on MRP 1 View
Below is a detailed explanation of how Error Total & MAD is being calculated (I have shown the formula as per excel). Remember we wanted to know MAD calculation because it’s in calculating safety stock and eventually automatic reorder point calculation.
Error Total: A forecast error is a difference between the forecast value and the actual consumption value of the same period. The error total describes the sum of the deviations over the periods, taking the plus or minus sign into an account. The error total helps check the validity of the forecast model in operation. If a model is still valid, you can assume that the error total is distributed normally and has an average of zero.
ET Calculation
As shown above, based on Original forecast, system carries out Ex-Post forecast. Difference between Corrective Historical Forecast – Ex post forecast is giving Deviation in that period. Sum of each deviation converted to absolute value gives Error Total. Below is the formula.
ET Calculation
MAD: Below shows how MAD is calculated:
MAD Calculation\
Tracking signal (TS): The tracking signal (TS) helps identify structural interruptions by putting the error total in relation to MAD. If the error total rises or falls sharply in relation to MAD, this means that the consumption and forecast are moving further apart.
- TS = Error Total / MAD
- The TS is compared to the tracking limit specified in the material master. If the TS exceeds the tracking limit, the MRP controller receives an exception message in the form of a note advising that the forecast model should be checked.
- The tracking limit is automatically set by the system. The default value is 4. However, you can change it while maintaining the material master record.
Since now we know how system is calculating automatic reorder point, here are the other alternatives to run the program and calculate automatic reorder point.
- Individual forecast: T-code: MP30 (or T-code: MM02 which I shown above)
- Total forecast: T-code: MB38 or MPBT.
You can print the list online or in the background mode. T-code: MP39 or MPDR.
Conclusion:
- Automatic reorder point calculation is another great way to manage inventory for class B and C items based on historic consumption.
- Automatic reorder point planning helps to bring on-hand inventory down
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Reference: Forecast Formulas
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Excellent demonstration. Love Excel formulas to understand the calculation. Thank you for sharing.
Ravi Dave I read part 1 and 2 both, you have used very useful demonstration data and realistic examples. Thanks for sharing...
Hi Saniket,
I appreciate your feedback. I am glad that it's helpful for the community.
Regards,
Ravi.
Appreciate your Blog , but i have these questions
How the numbers of MAD is being calculated
And how to calcutae daily requirement for Reorder Point Calculation ?
Also why you have defaulted Delta=.30
Hi,
I am glad that it's helpful. Here is the actual Excel calculation. I have uploaded the file on google drive. You will get it if you go cell by cell on the MAD column.
https://docs.google.com/spreadsheets/d/15hx5saW3u6y7LyFTRxdeN1UyUG8f4yQF/edit?usp=drive_link&ouid=103057080430654399105&rtpof=true&sd=true
If you really want to debug, then put a breakpoint at."
MAD is calculated in Program LSPRGF00 Form MAD_BERECHNEN.
Line RECHFELD2 = PCOM-VMMAD + PCOM-DELTA * ( RECHFELD1 - PCOM-VMMAD ) / 100 calculates the MAD."
My understanding is SAP uses forecast and Ex forecast to calculate daily requirements.
Delta comes as default based on the forecast model. I have selected it automatically.
Regards,
Ravi.
Hello, I did not see from the excel calculation how you arrive at 148 Reorder Point. Can you please share.
Thank you. Your blog is very helpful. I'm glad to read it.
Hi,
I am glad it's very useful. I have published the calculation on Google Docs. Here is the link: https://docs.google.com/spreadsheets/d/15hx5saW3u6y7LyFTRxdeN1UyUG8f4yQF/edit?usp=drive_link&ouid=103057080430654399105&rtpof=true&sd=true
Regards,
Ravi.
Hello,
Prompted with Unauthorized 401. I sent a request for access please.
Thank you.
Hi Marilou,
I have given access. Can you please try again?
Regards,
Ravi.
Awesome article,very easy to understand, it helped us to resolve our production issue.
Thank you !! I appreciate your comment.
Regards,
Ravi.
Hi, This is very helpful and very well explained.
Regards,
Dev.
This MRP concept is not easy to understand on your own, so this blog makes it very simple and easy to understand. Thank You
Very nice article indeed. Thanks a lot.
Excellent Document, Thanks For Sharing