1. Why Vendor ROI Models Fail CFO Review
Most software vendor ROI calculators produce fantasy figures. They assume that if an automated tool saves 30 minutes of a staff member's day, 100% of that time converts directly into payroll savings. A Chief Financial Officer knows this is false: partial time savings rarely eliminate full-time headcount, and automation shifts human effort toward exception handling and verification. To build a financial business case that survives board review, an IPA ROI model must incorporate explicit, conservative operational haircuts.
2. Modelling Labour Released (The 70% Haircut Rule)
When calculating gross labour cost released, the formula starts with full-time equivalent (FTE) count, fully loaded annual salary (including benefits, allowances, and overheads), and the percentage of time spent on automatable tasks:
Our model applies a deliberate 70% haircut (multiplying by 0.70) to this figure. Why? Because automated processes still generate edge-case exceptions, require periodic human review, and leave residual tasks that staff absorb. Crediting only 70% of theoretical time savings ensures the business case remains defensible under financial audit.
3. Modelling Exception Avoidance (The 60% Haircut Rule)
Manual re-keying errors cause rework costs, vendor payment penalties, and customs filing delays. The gross current error cost is calculated as annual transaction volume multiplied by error rate and average rework cost per exception:
Straight-through processing removes a significant portion of manual errors, but complex edge cases persist. Therefore, our ROI model applies a conservative 60% haircut (multiplying by 0.60) to exception savings. Crediting 60% of current error costs prevents over-promising on error elimination.
4. The Complete Net ROI & Payback Formulas
Net annual benefit and payback period are calculated using the following formulas:
Gross Annual Benefit = (Gross Labour × 0.70) + (Current Exception Cost × 0.60)
Net Annual Benefit = Gross Annual Benefit − Annual Run Cost
Payback Period (Months) = (One-off Build Cost / Net Annual Benefit) × 12
3-Year Net Value = (Net Annual Benefit × 3) − One-off Build Cost
5. Post-Deployment ROI Tracking & Auditability
An ROI model must be validated post-deployment. By tracking actual straight-through processing (STP) rates, cycle times, and exception queue volumes via operational dashboards, finance teams can measure actual savings against baseline assumptions ISO 42001 Standards.