Write-off certain amt of item value from inventory to expense every month based on item life period

Hi Experts

We are having small value and small life period items.

e.g. Chick Crates – Life period is 3 to 4 years

       Egg Boxes – Life period is 2 to 3 years.

We are maintaining these small value items as inventory items and included in inventory valuation. 

There is a business requirement to write of certain amount in every month from inventory to expense based on the item life period.

How we can fulfil this requirement in Oracle Inventory Module.

Thanks

Karthikeyan