1 What is the Basic Requirment of Order Planning in EP module?
2 What is neccessary work to do for apply of EP Module in running software?

Brij kishore:)

You have to maintain the order system as Planned in the Items-Ordering form and then maintain the Items-Planning form for all the items where you would like Order planning to generate the orders.You also have to add a appropriate figure inthe order horizon to generate the planned orders in the system.
You have also to Maintain the EP parameters , scenarios etc

Before this is done you have to just check if the BOM and the Inventory of the items are OK since the system is going to generate planned orders based on the BOM and the System inventory. This can be regarded as the basic requirement for implementing the Order planning