Purchase Order - Field Calculations

Purchase-invoice lines

Summary section and invoice main grid for PO invoices

Category =	Sum of the invoice lines total amount those are matched and have a category.
OpenAmount =	Sum of the invoice lines those are not matched and do not have any category.
MatchedAmount =	Sum of (il.Quantity * PurchaseOrderLine.UnitPrice * (1 - PurchaseOrderLine.DiscountPercentage / 100) - (PurchaseOrderLine.DiscountAmount * il.Quantity / PurchaseOrderLine.QuantityOrdered)) * (1 + PurchaseOrderLine.VatPercentage / 100).See Note 1 Below
TotalAmount/Invoice Total Amount =	Header Total Amount.
MatchedLineDeviationAmount =	Sum of Matched InvoiceLines Total Amount - MatchedAmount; See Note 1 Below
InvoiceDeviationAmount =	TotalAmount - SumOf InvoiceLines Total Amount.
Rounding =	InvoiceDeviationAmount + MatchedLineDeviationAmount.

Note 1 Invoice line values are ignored for these calculations if the invoice lines are matched with a service item good receipt.

Purchase Order Lines

Top right grid on the PO information view of invoice detail page

AvailableNetAmount =	PoLineUnitPrice * QuantityAvailable * (1 - DiscountPercentage / 100) - DiscountAmount * (QuantityAvailable / QuantityOrdered);
InvoiceNowNetAmount =	PoLineUnitPrice * QuantityMatched * (1 - DiscountPercentage / 100) - DiscountAmount;
InvoiceNowTotalAmount =	(PoLineUnitPrice * QuantityMatched * (1 - DiscountPercentage / 100) - DiscountAmount) * (1 + VatPercentage / 100);
RemainingNetAmount =	PoLineNetAmount - SumOfMatchedInvoiceLinesNetAmount;
Available Quantity =	If GRN is enabled it is as same as GRN received quantity Else  Initial value will always be received quantity But when update comes from ERP to existing PoLines it is re-calculated as;
Available =	requestPoLine.QuantityReceived - (requestPoLine.QuantityInvoiced + purchaseOrderLine.QuantityMatched + purchaseOrderLine.QuantitySentToErp)

Source: https://semine.visualstudio.com/Bilagos/_wiki/wikis/Bilagos.wiki/322/Calculation-of-some-important-fields-on-purchase-order-lines