When an asset is being worked on usually it isn't usable or active. To help keep track of an asset's status users can change the status from the Work Order > Asset Grid. This can also be used to change the status back when the work is done.
How To Change Asset Status
Change the status in the Asset grid.
Go to the Work Order > Asset tab and select the asset(s) that need a status change.
Right-Click on the asset and select Change Asset Status, the shared Status pick list will appear
Select a status and click
The status for the selected asset(s) will automatically change.