Project WIP Ledger Accounts Location In Balance Sheet

Hi All

I have one query regarding the placement of the "Project WIP- Invoice On Account"and “Project WIP- Sales Value” ledger accounts in the balance sheet, where these accounts should be shown under Assets side or the liability side (as per the accounting standards).

Why i am asking is due to the advance payment of the customer, as when we receive the advance which is the liability and when we post the Project invoice following is the entry:

Project WIP Invoice on- Account Cr.

Customer Dr.

Please advise me on this, thanks in advance.