In odoo we can take the printout of customer due payment. This is a default feature. But in it, the calculated total due amount is wrong in the case of partially paid customer. For eg, a customer makes an invoice for an amount 2000. But he already made a partial payment of 1000 and when we take the customer due payment report, it will show the due amount as 2000. It doesn't consider the partially paid amount. So here we fixed the issue by correcting the calculation of the due amount.