Previously we discussed why it's important to start showing the system to users as soon as possible. Today we will elaborate on the third tip which states that buying channel design should be kept simple, standardized and flexible.
One of the main objectives of a P2P implementation is to ensure users can request and order goods and services in a user-friendly way. Especially if there is no legacy Purchase Order (PO) system, we see that a large variety in buying channels has been evolved over the years. Lease cars are ordered via an external portal, the IT department created a separate tool to request IT equipment, office supplies are requested via secretaries and we to login to a webshop of a supplier with a shared email address and password to order business cards. All examples of different buying channels that have not been formalized over the years.
We recommend to start with a clean sheet at the moment you start with your P2P implementation. Define a fixed set of rules and minimize the exceptions to these rules. One should begin with the four standard ways to buy: (1) free text request, (2) blanket PO, (3) catalog or (4) invoice directly against a contract. Define logic to determine which categories should fall under which buying channel and how the approvals should look like. E.g. all office supplies should be ordered via a catalog and we use the standard approval logic. Only divert if there are grounded reasons that indicate that a certain type of product should be ordered in a different way or require a specific approver.