Hi,
Can anyone please tell me what is the main purpose of doing inventory closing in AX?
Thankyou so much
You should try looking at the available documentation,
Hi Evangeline,
I would say Inventory close has three functions.
It closes a period for inventory, so that adjustments to inventory cannot be made.
It assigns the cost of ‘receipts’ (e.g. purchased or produced items) to ‘issues’ (e.g. sales orders) using the rules of the item’s inventory model.
It updates the cost of ‘issues’ if the cost of the related ‘receipt’ has changed.
It is pretty much mandatory to use it if you use any of AX’s actual costing methods (except Moving average).
Also the standard cost method would not need an inventory close.
The AX by default issue the material with wt. avg. The inventory close or recalculation will update the issue cost as per the actual costing method.
I read a Microsoft post that said it was not needed for standard costing, but they recommend you run it on batch anyway. That kind of indicates something may fall through the gaps [:D]
It closes the period for inventory, no matter which costing method is used.
And, from the Hands on Lab ‘Costing and Inventory valuation’:
In Microsoft Dynamics AX 2012, an inventory close is recommended for all inventory models, including standard cost.
Per this blog post, Inventory close will create records in InventCostTransSum for a standard costed item.
http://blogs.msdn.com/b/axinthefield/archive/2011/06/01/standard-cost-in-ax-2009.aspx
I also read recently that Inventory close can cause variance postings on standard costed items in a production scenario, but now I look again, I can’t find where I saw this 
Inventory closing is an activity performed in Dynamics AX to represent to close of the financial period and/or fiscal.
This ensures the inventory sub-ledger is accurate to the date with the value in General Ledger and does it by settling the issues with the receipts in principle with the inventory costing model.