The invoice sitting in the site manager's car
A construction firm loses early-payment discounts — not for lack of cash, but because approval travels the country on paper.
The bottleneck is paper-based approval — even though site management is only 31 % utilised. Capacity is not missing; a digital route is.
9.4working days
In 8 of 10 cases between 3.2 and 21.5 days.
Freigabe Bauleitung
In 71 of 100 simulated runs this step was the hold-up.
€29,000
Per year. Estimated between €21,000 and €38,000.
€21,000
Per year. Estimated between €14,000 and €27,000.
Invoice approval
- Industry
- Construction
- Size
- 80 Mitarbeitende
- Cases per year
- 4,200
- Fully loaded rate
- €68 / h
- Simulated runs
- 500
- Date
- April 2026
Accounting regularly pays without taking the early-payment discount. The in-house accusation: accounting is too slow. Accounting says it gets the invoices back too late.
4,200 incoming invoices a year, five steps, three roles, at a €68 fully loaded rate. Modelled and simulated over 500 runs.
Six steps, four roles, one measurable path
The process modelled in FlowVisual. ↯ marks a media break — the point where data is retyped from one system into the next.
| Step | Role | System | Duration P10–P90 | Bottleneck |
|---|---|---|---|---|
| 01Rechnungseingang | Buchhaltung | E-Mail / Papier↯ | 3–8 min | 3 % |
| 02Sachliche Prüfung | Buchhaltung | ERP | 5–15 min | 8 % |
| 03Freigabe BauleitungBottleneck | Bauleitung | Papier / Post↯ | 5–20 min | 71 % |
| 04Kontierung | Buchhaltung | ERP | 4–10 min | 9 % |
| 05Zahlung | Buchhaltung | Banking | 2–5 min | 9 % |
500 runs, one clear answer
Every chart below shows before against after. Values are labelled directly — the colour is a second signal, never the only one.
88
Rechnungen/Woche
22 %
3.2–21.5working days
Freigabe Bauleitung — 71 %
Accounting is not the problem. In 71 % of runs the bottleneck is approval by site management — the only step that runs on paper and has to be physically transported.
The actual work in that step takes 5 to 20 minutes. The waiting takes days. A step with almost no work blocks the entire flow.
Site management utilisation is 31 %. That is the key sentence of this analysis: the bottleneck is not overloaded. This is not a capacity problem, it is a transport problem. Hiring would have changed nothing.
Approval moves into the ERP. On the phone.
Approval would be granted on mobile in the ERP instead of on paper in the office. Invoice intake would switch to e-invoicing so the media break at the start disappears.
This would not be a digitalisation strategy, but a single lever — chosen because the measurement names it.
Median lead time down 67 %
- How long it takes
- 9.4 → 3.1 working days
- Throughput
- 88 → 92
- Days over capacity
- 22 % → 8 %
- Saving per year
- €21,000
Median lead time falls from 9.4 to 3.1 days, bringing the company back inside the usual 14-day discount window even in the P90 case (7.2 days).
Site management remains the most likely bottleneck (42 %) — but now at a level that no longer breaks the payment run. Accounting drops from 92 % to 74 % utilisation without a single hire.
Two thirds of the saving comes from recovered discounts, one third from eliminated rework.
What this analysis cannot tell you
Every measurement has limits. A measurement that hides them is advertising.
- 01
This is a sample analysis. The figures are constructed, not measured at a client.
- 02
The discount saving assumes suppliers grant 2 % at 14 days and that invoices are approved in full. Disputed invoices are not modelled.
- 03
Waiting times were estimated as a distribution, not pulled from system logs. With real data they would likely be more erratic.
- 04
Switching to e-invoicing carries one-off costs that are not part of this calculation.
Your process will look different.
This analysis is a sample. Your numbers are not. With FlowVisual you model your own process and get the same evaluation — on your machine, with your values.