Settings
It depends on the settings if a purchase order can be generated.
->RetailVista -> Extra -> Settings -> Section: Sale orders -> Tab: General
SaleOrders_IsGeneratePurchaseOrderWhenSufficientFutureStock: Change the setting to “Yes”, if you want to be able to generate purchase orders when the future stock level is sufficient for the sales order.
SaleOrders_SaleOrderToPurchaseOrderMethod: Select SaleOrderAmount or StockAmount, depending if you want to generate purchase orders based on sale order amount or based on stock amount.