The status of a purchase shows how far it has progressed. Planned means the contract or purchase hasn't been ordered yet. Purchased means the contract has been signed or the purchase completed. Ongoing is used when start, end and total are not defined, for example for hourly work.
The statuses
Planned: The purchase will be made later, or the contract is being negotiated. You enter the expected amount so it's included in the final forecast.
Ongoing: The work has started, but without a fixed total or period, for example a consultant invoicing hours on an ongoing basis.
Purchased: The contract has been signed, or the individual purchase has been completed. Enter the actual amount.
How to change the status
Open the purchase and select Edit.
Change the Status on the cost line. If the purchase has several lines, you can use Set all.
Adjust the amount if the final amount differs from the planned one.
Save.
Why does the right status matter?
The overview on the production code distinguishes between Planned and Purchased, so you can see what is committed and what is still an estimate. Set the purchase to Purchased as soon as the contract or assignment has actually been ordered.