If there is a need to buy or produce the part it will be linked to ‘PENDING’.

If the part is linked to PENDING with the additional text "Available Purchased/Production", a supplier document/production order or goods reciept (SPO, SOA, PWO or SSA) exists. 
This happens if you for example place a purchase order after the production order (PWO) has been released and prior to the stock assignment (SAR) optimize job.
You have the option to 'Inspect SAR' to see the linking and re-link if necessary.

To do this, you enter the Stock assignment register (SAR) and remove assignment from pending, 
then reassign the quantity to the supplier document or production order ( SSA, SPO, SOA or PWO ) you want.

Note that the confirmed delivery date on a supplier order or production order (SPO/PWO) might need to be changed in order to get the part when needed in the operations.