Timing the invoice to pay process honestly is uncomfortable and useful. The hands-on work from an invoice arriving to money leaving is typically under an hour. The elapsed time is commonly weeks. Two waits account for almost all of the difference, and both are addressable without changing how any of the work is done.
Wait one: reaching an approver
An invoice sitting with the wrong person, with somebody on leave, or in a queue nobody owns. Routing to a named approver by cost centre and value, automatic cover during declared absence, and escalation to a named alternative after a set period remove most of it. This is the largest single component in most organisations.
Wait two: the payment run
An approved invoice waiting for the next scheduled run. Legitimate, and worth choosing deliberately: weekly rather than fortnightly halves the average wait at no cost, and running more often than weekly mostly adds administration. The point is that the rhythm should be a decision rather than something inherited.
The wait nobody counts
Between an invoice arriving at the organisation and reaching payables, when it landed in an individual's inbox rather than a monitored address. This is invisible in most measurements because the received date is recorded when payables sees it, and it is often the largest hidden delay of the three.
What to do with the measurement
Take fifty recent invoices and record the date at each event. The gaps will be obvious within an hour. Attack the largest one, which for most organisations is approval routing, and re-measure afterwards. That loop is the whole of process improvement in payables, and it needs no software to start.
Questions people ask about invoice to pay process
How often should payment runs happen?
Weekly suits most organisations. Choose deliberately and tell suppliers, since most chasing is a supplier trying to establish a date.
What should we measure?
Elapsed days at each step, as a distribution rather than an average. The tail is where the complaints and the cost are.
Can suppliers help?
Yes: quoting the order reference and billing the address you asked for removes two of the commonest causes of delay.
Does automation shorten both waits?
It shortens the approval wait substantially through routing, cover and escalation. The payment run wait is a scheduling choice rather than a software one, and shortening it costs nothing but a decision.