Most automation projects fail not because the technology breaks, but because nobody calculated whether the investment made financial sense. A €10,000 automation saving €3,000/month pays back in under four months. The same automation saving €500/month takes nearly two years - by which point requirements have changed. The difference is math done upfront.
The core formula
Monthly savings = (hours saved × hourly cost) + (errors avoided × cost per error) + opportunity value gained.
Payback period = total automation cost ÷ monthly savings.
Annual ROI = ((monthly savings × 12) − total cost) ÷ total cost × 100 %.
The hard part is measuring inputs honestly.
Step 1: Measure the current process cost
Document the real cost of doing it manually:
- Labour: people × hours × fully loaded hourly cost (salary + benefits + overhead, typically 1.3-1.5× gross in Croatia)
- Errors: frequency × cost per error - a €5 data entry error causing a €500 shipping mistake is a €505 error
- Opportunity: revenue work those people could do; cash flow lost to slow processes
Example: manual invoicing. 12 hours/month × €35 = €420 labour; 3 errors × €80 = €240; €200 delayed collections. Total: €860/month.
Step 2: Estimate the automation cost
Include everything, not just the build:
| Component | Range |
|---|---|
| Discovery and scoping | €1,000-€3,000 |
| Development | €2,000-€15,000 |
| Integration | €1,000-€5,000 |
| Training and change management | €500-€2,000 |
| Annual maintenance | 15-25% of build |
For the invoicing example: €6,000 build + €1,000 annual maintenance.
Step 3: Calculate payback
Assume automation eliminates 85% of process cost = €730/month saved.
- Payback: €6,000 ÷ €730 = 8.2 months
- Year 1 ROI: (€8,760 − €7,000) ÷ €6,000 = 29% (build + maintenance vs build cost)
- Year 2 ROI: (€8,760 − €1,000) ÷ €6,000 = 129% (maintenance only vs same build cost)
By year two, savings more than double the cost. Strong investment.
When the math says “don’t automate”
- Payback exceeds 18 months - too much risk of obsolescence
- Monthly savings under €300 - maintenance eats them
- The process changes frequently - you will rebuild every quarter
- Error rates are already very low - time savings alone may not justify the spend
Hidden variables most calculations miss
- Adoption rate. If only 60% of the team uses it, you capture 60% of savings. A €500 investment in training can double effective ROI.
- Integration maintenance. APIs change. Budget 15-25% of build cost annually or the automation breaks within 18 months.
- Scale effects. Volume grows; automation scales better than people, so ROI improves over time.
For any process, fill in: monthly hours, hourly cost, errors × cost, opportunity cost → total monthly process cost (A); build cost + maintenance → total Year 1 cost (B). Payback = B ÷ (A × 0.85). Under 12 months - automate. 12-18 - proceed with caution. Over 18 - pick a different process first.
Frequently asked questions
What if I cannot measure the process cost accurately? Start with time. Ask the people doing the work how many hours per week they spend, then multiply by hourly cost. Even a rough estimate beats guessing.
Should I include soft benefits like employee satisfaction? Not in the primary calculation. They are real but hard to quantify - use them to break ties between candidates with similar hard ROI.
How do I handle one-time vs recurring savings? Only recurring savings compound into strong ROI. One-time savings (like data migration) must justify the cost on their own.
Related articles
- 8 processes worth automating first
- Signs your business needs process automation
- AI + automation stack for SMBs
Want to calculate ROI for your process?
Book a free Discovery call. We map your process, estimate the build, and calculate payback - before any commitment. Reach info@tsunami-digital.com or use our homepage form.