Reordering Policy Order

Hi all,

can anyone explain how is reordering policy order work in NAV?

i have a ilustration like this:

Reordering Policy = Order

Reserve = Always

Item tracking code = SN Specific tracking

Replenishment type = Purchase

Inventory (initial stock as per date 12/31/12) = 10

Sales Order (as per date 01/05/13) = 5

when user input sales order, system will automatically create reservation entry for this sales order from initial stock.

and because of some consideration, user cancel the reservation.

when we run calculate plan in requisition worksheet, system will suggest to create new purchase order (reservation entry with type requisition line).

why system didnot create a reservation from initial stock? and how can i achieve this result?

any suggestion or feedback will be appreciated.