A purchase order process flowchart drawn as a single line of boxes hides the thing that determines how well the process runs, which is who owns each step. Drawn with three lanes, for purchasing, whoever receives deliveries and payables, it usually reveals that one lane has nobody in it, and that lane is the receiving one.
Purchasing's lane
The request, its approval, the order and its issue to the supplier. Clear ownership, clear measures, and generally the best-documented part of any purchase order process. Chasing late deliveries also belongs here, using the aged open-order report, though it is often nobody's explicit job.
The receiving lane
Recording what arrived, when, against the order line. In most organisations this is done by operational staff who report to neither purchasing nor finance and are measured on neither's outcomes. Drawing the lane and finding it unstaffed is frequently the most useful five minutes of a mapping exercise, because it names the problem precisely.
Payables' lane
The invoice, validation, matching, exception routing, approval, coding, payment and remittance. Well understood and heavily documented, and dependent on the other two lanes for its inputs. Marking that dependency on the chart, with the elapsed time at each handoff, is what turns a diagram into an improvement plan.
Questions people ask about purchase order process flowchart
Should exceptions be on the chart?
Yes, at least the four main branches with owners and target times. A chart showing only the clean path describes the minority of the effort.
How detailed should it be?
One page. Beyond that it starts describing system screens, which date as soon as anything changes.
Who should draw it?
All three lanes together. It is often the first time the handoffs have been discussed explicitly.