How MRP will work?

[avinash_sharma]

Hi All,

Below is the description of the scenario :

Suppose X is a in-house production material. And 'A'(Externally procured material) is one of the components in the BOm for X.  Now a SO is created for the X and let the delivery date be 25/06/2012. Based on  Goods issue date  in SO which I made it to 21/06/2012 a MD04 entry is created(Just to test I made the Production time to 0 days). Now what I want to know is that on what basis the entry for 'A' will be created in MD04(i.e; procurement proposal for A). The Planned delivery time for A is 1 day. I was not able to figure this out, as there were many depreq for the same date in MD04. Can anyone tell me what will be the  requirement date and how MRP calculates it?

And, if we know the Planned order is it possible to know from which SO it has been triggered ?

Let me know if any other information is required.

Regards,

Avinash

[Former Member · Accepted solution]

Hi Avinash

Suppose X is the FG and requirement date is 21st for X.

Since it is inhouse produced materials, system will check the inhouse production days defined in MRP2 view to calculate the basic start date and Finish date. There are two things here to define the inhouse prod days. one is independent lot size prod days which is in MRP2 view.

Another one is lot size dependent in house prod days which we are entering in work scheduling view. System will calculate the in house prod days based on the lot size dependent data you have given in work scheduling view.

for example - if you have maintained the base qty is 300 and processing time is 1 day in work scheduling view and your planned order qty is 3000, den system will take in house prod days in 10 days.

the your start date of your material X would be in 12th and finish date would be on 21st.

so the dependent req to the material A would be on 12th.

since it is a procurement material , system will check the planned delivery time and GR processing time . If both includes 5 days, den your start date for material  A would be on 8th and finish date would be on 12th.

This is how MRP defines the dates.

In between suppose if your operation routing timings is more than your inhouse production days den system will adjust the basic dates based on the routing timings after converting to Production order. For this you have to do settings in OPU5 as adjust basic dates in adjust scheduling at plant level.

Hope this will clear your doubt.

Santhosh.

[avinash_sharma]

Hi Senthil/Pavan,

Thank you for the details.

Yes the because of the Lead Time maintained in Routing, Order is scheduled this way.

Now one thing pops into my mind is that, in any case scheduling data from the Routing will be used in Production Orders then what is the point of maintaining Planned Production data(Just to be used by MRP while creating Planned Order !). Is there any real logical reason for using The Planned Production Order time(maintained in Material Master).

Regards.

[avinash_sharma]

I also did some other tests. I first created a Planned order for the same material with end date as 06/29/2012, this time system used Planned Production time(7 Days in Material Master) and calculated start date as  06/22/2012.

Then I converted this Planned Order to Production Order, below is what happened :

Above you can see that even the basic start date is changed ! I expected it to be 06/22/2012.

But in relative Planned Order:

any Idea on this.  !

[Former Member]

Hi Avinash,

While running MRP, for the field 'Scheduling,...you can choose the option '2 - Lead time scheduling & Capacity Planning' instead of '1- Determination of Basic dates in Planned order'.

This way, even the planned order will be scheduled based on the Routing,... and the scheduling data will match up when converting them to the Production order as well.

Basic Scheduling is done in ref to the In-house production time in Material master; and Lead time scheduling is done in ref to the Routing.

Just to add... The Inhouse production time in Material master is entered in Days... so this is basically to help us to get the overall scheduling on 'Date' basis; whereas the routing entries could be in hours or even minutes,... and this is required to accurately schedule and plan the capacities.

If the expectation at the time of creating the Planned order is to get the general scheduling date, it is fine to use 'Basic date' option. And when we actually convert into a Production order, we can get into the actual capacity planning and Scheduling acivities.

But, there are many cases where even Accurate schduling / capacity planning activities are done (like REM) or many discrete mfg situations,... even at Planned order level. In these cases, we can set the entry '2-Lead time scheduling and Capacity planning'

Thanks

Senthil

[avinash_sharma]

Hi All,

Thank you very much for the help. The strategy being used is MTO. Need your expert advice on following questions :

When we create  a SO, at first system automatically creates shipping details(like delivery date, etc.), though we can alter it but I want to know the schedules calculated by system -- are they based on availability check and production time(in material master).

And it will be help full if could shed some light on Start date and end date maintained in production order. Just for a test I created a production order(In house production time --  7 days), but system calculated this to 1 day. So if today is start date then tomorrow will be the end date. What could be the possible reasons for this ?

[Former Member]

Hi,

q : When we create  a SO, at first system automatically creates shipping details(like delivery date, etc.), though we can alter it but I want to know the schedules calculated by system -- are they based on availability check and production time(in material master).

Yes, system considers the availability check and configurations in SD (Scheduling By Sales Document Type) while making schedules. It is also possible  that system automatically shifts to forward scheduling if availability is less, or dates calculated lies in the past dates. System considers here the time you maintained for pick/pack, load or transportation.

q : And it will be help full if could shed some light on Start date and end date maintained in production order. Just for a test I created a production order(In house production time --  7 days), but system calculated this to 1 day. So if today is start date then tomorrow will be the end date. What could be the possible reasons for this ?

Production time is considered for scheduling in production activities. When production order is scheduled it will consider the material master data to calculate basic dates but not scheduled dates. If you check order details (CO02) you can see these things.

Also check the routing created for the material for which yoou are creating order. If time maintained in routing is 1 day then system takes routing time to calculate scheduled dates. Routing is mandatory to create an order.

Routing data is more accurate than material master data.

check this link - http://help.sap.com/saphelp_erp60_sp/helpdata/en/f4/7d297144af11d182b40000e829fbfe/content.htm

Regards,

Pavan

[Former Member]

Hi Avinash,

Is the Requested delivery date (Schedule line date) on the Sales order set to tomorrow?

What is the sum of lead times for Operations in the Routing? Is it One day or less?

And, can you please check if the 'Fixed Date and Quantity' indicator is 'Ticked' in the Sales order (Schedule line tab)...

Thanks

Senthil

[Former Member]

Hi,

The scheduling part of MRP run will determine the dates.

By default SAP will always do backward scheduling but there are quite number of other types of 

scheduling also possible.

We will consider here the backward scheduling(easy to understand).

Suppose the delivery date of material is 30/06/2012. (assuming on this date materials should reach customer)

taking 30/06/2012 as end date system deducts delivery time in this to calculate ready for dispatch date -- > system deducts pick pack time to get availability date --> system deducts good reciept production time to calculate production finish date --> system deducts in house production time to calculate production start date -- > system deducts opening period to calculate order opening date      ---> if we are assuming all raw materials are available on order opening date then it deducts delivery time ot goods reciept processing time to calculate Purchase order date (for rawmaterials)     -- > then it deducts purchase procesing time to get PR date.(starting point of production)

If you still want to go back then before PR creation there may be quotation processing to procure the materials.

If by deducting time, system calculated date falls in the past then it automatically makes today scheduling. Today scheduling is nothing but forward scheduling considering today as the starting date.

If material involved are more then purchase, production and sales are more likely to overlap each other.

Above description should give you a brief idead how the scheduling works. Let me know if you have any other concerns.

For second part:

You can check planned order which has been created from a sales order if you are using MTO production strategies. They have direct link in that case. If MTS strategy is used then it may not possible to have a direct link.

Regards,

Pavan

[avinash_sharma]

Hi Pavan,

Thank you for providing the explanation. Could you please help me in understanding, what exactly Opening Period means ?  And where can I see it ?

Thank you!!

[Former Member]

Hi Avinash,

Opening period is part of the 'Scheduling Margin Key' entry in material master (MRP2 view).

Please refer to the links below -

http://help.sap.com/saphelp_40b/helpdata/en/f4/7d297144af11d182b40000e829fbfe/content.htm

http://scn.sap.com/thread/1554548

http://help.sap.com/saphelp_45b/helpdata/en/3c/e92c7dd435d1118b3f0060b03ca329/content.htm

Thanks

Senthil

[former_member698542]

Hi Avinash,

AS per the MRP it will arrive the availability date for the produced material from the requirement date of the sales order. If the material is to be issued on 21/6/2012 to the sales order, it will be produced and ready by 20/6/2012. Since you have maintained the in-house production 0 day, if procured material is available in stock, it will be ready on the same day. Other wise system will generate PR for the procured material and the lead time will be considered for the availability of the raw material. Accordingly the available date of the produced material will change.

If you want to know the sales order number of the planned order, then you have to maintain strategy 20 make to order in MRP-3 view. Then only the sales order number is updated in the planned order.

Thanks and regards

Murugsan