When you decide to take the “leap” to convert to material ledger, you need to make sure that certain prerequisites are met in order for the conversion to run smoothly. For example, the following tasks will need to be completed (depending upon your setup):
(1) Close all open purchase orders: this can be done by setting the “Delivery Complete” indicator which is located in the “delivery” tab of the Purchase order Line Item section. You can use transaction MEMASSPO to accomplish this task.
(2) Archive Obsolete Purchase Orders: this can be done by using archiving object MM_EKKO;
(3) Close all open production orders: this can be done by marking them as “Technically Complete” and “Closed”. You can do this by using transaction COHV for Production Orders or COHVPI for Process Orders;
(4) Perform maintenance of the Goods receipt/Invoice receipt Account: This can be done by going to transaction MR11 and executing it for historical purchase orders that have either been goods receipted and not invoiced or invoiced and not goods receipted. When this transaction is executed and posted, the GR/IR account can be cleared for old open items;
(5) Archive Obsolete Materials: To do this you first need to flag the materials for deletion. This can be done en masse by using transaction MM70. Then you can go to transaction MM71 to archive the material, using the archiving object MM_MATNR.
The idea is that the more data you can reduce by closing or archiving any irrelevant or obsolete beforehand, the more efficient the material ledger startup program will run. This startup program considers all materials and purchase orders in plants that are activated for material ledger.
You also need to make sure that all the material ledger customizing settings are complete. To do this you can go to transaction CKM9 and execute it for a specific plant. This will show the following:
(1) Whether material ledger is active;
(2) Whether the relevant plant is assigned to a valid company code;
(3) Whether a Currency and Valuation Profile is active and assigned to the controlling area (for parallel valuation purposes);
(4) Whether the currency settings for Material Ledger are aligned with those of FI and CO (depending on the customizing settings in this regards);
(5) Whether other material ledger settings such as Actual Costing, Activity Update and Actual Cost Component Split, are activated;
(6) Whether the Material Ledger document numbers are set up.
(7) Whether accounts have been assigned appropriately to the relevant account determination tables.
Once these prerequisites have been carried out, then you can run the material ledger startup program (transaction CKMSTART). This program needs to be run almost immediately after the configuration of material ledger has been transported into the production system, otherwise any inventory movements that take place before this time will produce errors. Also, make sure that you create a backup of the production system before the transaction is run, and that everyone is out of the system at the time. Always run the program in test mode first, and execute it in background mode.