Production and Purchase item

in navision, I have an item which I am purchasing and even producing the same item.

I want to maintain a single item, how can I manage the same in differentiating that which lot is production and which is purchase?

You will need a customization to accomplish this task and it will be quite extensive modification.

As sbhatbng (!) says, then this is not possible in NAV - at least not directly.

If you can break down your request, then you may be able to find a work-a-round for this.
So let me ask you why and where you need to see the difference? And why does this matter?

I can think of different ways to do this. Either you could use Variants. This would allow you create different Stockkeeping Units for own-production and purchased items. The SKU card would allow you to specify settings for the two “options”
The issue is then that your need to know which item to use when you create your sales orders.

Or you could use Lot No. management. If your item’s don’t have lot no.'s “naturally” (from the vendor and your own), then you could simply have two different lots: PRODUCTION or PURCHASE.
The issue here is that you would need to specify the lot no. and by that change your current process of both shipping and receiving.