SAP EWM Layout oriented storage control (LOSC) behind the scenes

[RudraNarayan]

In SAP EWM space, LOSC feature plays an important role in every project. This blog will help you to understand the background logic with scenario specific understanding.  It is bit technical so don't be overwhelmed , I've tried to explain in simple terms. Hope it helps. Enjoy the blog .🙂

Scenario 1: Product WT creation from  /SCWM/ADPROD or against WHR with full with drawl.  No pick point check in source storage type

Configuration:

Source Storage type:

LOSC:

Execution:

Product WT create

Note: This scenario behaves the same way if your rounding rule is '5' where we round to the multiple of available stock in this case at HU level & it matches the requested pick quantity.

Debug mode:

We can  see  the  main  program on the top  and  also in the call stack.

The FM is /SCWM/ROUTING_LAYOUT_CHECK   is mainly to check for LOSC.

Inside the FM we can see the highlighted code which checks
1. IV_FLGHUTO ( HU WT flag) 

2.  IV_HOMVE ( Important field for LOSC* we will see this further)

3. LS_VT331-PPNTA ( Pick point field in source storage type)

If any of the above fields are having value then it will eventually go to the main LOSC determination FM /SCWM/TROUTL/DET

which will check the entry from LOSC config settings shown above.

We see the IV_HOMVE is coming with value 'A' which then eventually checked and updated LV_HOMVE with 'C'

So, the question is how this IV_HOMVE is getting the values. 🤔

Let's go 1 step back in debugging to get the answer.

This is coming from the  below FM '/SCWM/TO_SRC_HU_HOMOGEN_SET'

called inside the FM /SCWM/REM_BIN_DET_INT 😇

If we see now inside the FM we can see that system checks what is the WT quantity (CS_LTAP-VSOLM) ,100 KG as shown below

and is it matching with the HU quantity (LV_QUANTITY) ,100  KG as shown below.

If yes, then it will eventually pass CS_LTAP-MOVEHU with value 'A' and then CS_LTAP-HOMVE is  marked  'X'

So far, we have these values,

but if you recall IV_HOMVE value inside the FM /SCWM/ROUTING_LAYOUT_CHECK  was 'A' not 'X'.  Therefore, we still need to see where this value is being updated. 
Here it is 

Note: You can notice here, CS_LTAP- MOVEHU value is passed into IV_HOMVE not CS_LTAP-HOMVE.

Now if we continue, we can see that it finds the LOSC settings ,

finally we will  have 2 WT's- 1 HU WT (open) and waiting product WT.

Scenario 2: Product WT creation from /SCWM/ADPROD or against WHR with partial quantity. 

No pick point check in source storage type

In this case the requested quantity 10 KG (CS_LTAP-VSOLM) is not matching with full HU quantity 100 KG (LV_QUANTITY)

therefore the value will not be set & code will return in the below FM /SCWM/TO_SRC_HU_HOMOGEN_SET

This will eventually not qualify for LOSC. Skipping the main LOSC FM.

Finally creating only 1 Product WT.

Scenario 3 : The storage type have pick point active and we have HOMVE ( whole HU) A for partial and C for complete HU pick scenario.

Configuration:

Source Storage type:

LOSC:

Execution:

a. Product WT creation for partial picking-

Debug Mode:

As pick point flag is active it will  always be going into the FM /SCWM/TROUTL_DET  via  /SCWM/ROUTING_LAYOUT_CHECK.

IV_HOMVE is initial, so it is passing 'A' into LV_HOMVE

It found the LOSC entry with IV_HOMVE ='A'

Finally creating 2 WT's- 1 active HU WT and 1 waiting product  WT

Similarly, lets see the complete HU pick case.

b. Product WT creation for complete HU picking.

The LOSC will find the correct entry with HOMVE ='C' and create the tasks.

Debug mode:

We can see that system has found LOSC searching with HOMVE value 'C'

Again, created 2 WT-s , 1 active HU WT and waiting product WT.

This concludes the blog. Thanks for reading and do share your comments.

Disclaimer:  Above logic is tested in demo systems but actual project scenarios might be different so please do the required due-diligence.

Best Regards,

Y K B B Rudra Narayan