From PERPWiki

Contents 1 Overview 1.1 Purchase Order 1.2 Shipment 1.3 Receiving 1.4 Invoice 1.5 Payment

Overview

The general process for Accounts Payable in pERP is:

[Create Purchase Order -> [Ship ->] Receive ->] Invoice -> Payment

This is not a rigid flow, and not all steps are required. For example, when you pay utilities, there is just Invoice and Payment. When there are physical goods, the process must start with a Purchase Order, because every step after that ties back to that order, either directly, as in the case of shipments, or indirectly, such as a payment on an invoice for an order.

pERP uses order_id + line_no as a unique key, and the Shipment and Invoice reference this key. Shipments via the Shippable interface, and Invoices via the Invoicable interface.

Purchase Order

Shipment

Receiving

Receiving gets the stuff we ordered into inventory. Receiving Flow

Invoice

Payment