The verdict in three sentences
A market PSA (Professional Services Automation) at 30-90 EUR/consultant/month covers staffing, time and billing for most firms. Custom development at 50,000-140,000 EUR is justified when fine staffing, per-mission margin tracking and your billing rules are your edge. The real lever: +5 to +12 points of utilisation, worth tens of thousands of euros of margin per consultant per year.
SaaS PSA vs custom development
A PSA is rented per consultant and standardises staffing, timesheets and billing. Custom fits your rate cards, per-mission margin and rebilling rules. 2026 order of magnitude:
| Criterion | Market SaaS PSA | Custom |
|---|---|---|
| Upfront cost | 2,000-8,000 EUR (setup) | 50,000-140,000 EUR |
| Recurring cost | 30-90 EUR/consultant/month | 1,200-3,200 EUR/month (maintenance) |
| Time to deploy | 4-8 weeks | 4-7 months |
| Predictive staffing | Basic | Custom |
| Per-mission margin tracking | Standard | Fine, per consultant/mission |
| Mission billing | Standard | Complex rules |
| Code ownership | No | Yes |
For a firm of 40 consultants at 65 EUR/month, the PSA costs 2,600 EUR/month, i.e. 31,200 EUR/year. Over three years: 93,600 EUR. Custom is justified mainly by the margin unlocked via utilisation, not licence comparison alone.
What tips the decision
Margin and utilisation functions lean towards custom:
| Function | 2026 impact | Verdict |
|---|---|---|
| Predictive staffing | Utilisation +5 to +12 pts | Custom |
| Per-mission margin tracking | +2 to +5 pts margin | Custom |
| Ruled billing | -20 to -40 % billing disputes | Custom |
| Timesheets | Reliable standard | PSA is enough |
| Workload forecasting | Faster decisions | Custom |
| Client portal | Satisfaction +10-15 pts | PSA is enough |
For a firm of 40 consultants billed at 700 EUR/day on average, winning 5 utilisation points means about 9 to 11 more billed days per consultant/year, i.e. roughly 6,500-7,700 EUR of added revenue per consultant. Across 40 consultants: over 260,000 EUR.
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Mini case study
Claire, partner in an HR consulting firm in New York (40 consultants, 700 EUR average day rate, 72 % utilisation), pays 2,600 EUR/month for a PSA. A custom project at 96,000 EUR, amortised over 4 years (24,000 EUR/year + 24,000 EUR maintenance = 48,000 EUR/year), must beat 31,200 EUR of licences. The 16,800 EUR gap disappears once utilisation gains 1 point (~52,000 EUR of firm revenue). With an expected +5 real points (~260,000 EUR) and +3 points of per-mission margin, net first-year ROI exceeds 250,000 EUR. Custom clearly wins at 40 consultants.
FAQ
How much does a SaaS PSA cost for an HR firm? Budget 30-90 EUR/consultant/month. For 40 consultants at 65 EUR, about 31,200 EUR/year, excluding a 2,000-8,000 EUR setup.
What budget for custom consulting software? Between 50,000 and 140,000 EUR depending on scope (staffing, margin, billing), plus 1,200-3,200 EUR/month maintenance. Timeline: 4 to 7 months.
Does custom really improve utilisation? Predictive staffing tailored to your missions typically delivers +5 to +12 points. At 40 consultants and a 700 EUR day rate, each point is worth about 52,000 EUR of revenue.
Can we keep our billing tool? Often yes: custom can connect via API, but embedding per-mission margin in one tool avoids double entry and disputes.
How fast does it pay off? From 30-40 consultants, the return is usually 6 to 15 months, driven by utilisation and margin.
Let's scope your project. Share your consultant count, average day rate, current utilisation and indicative budget: we cost PSA vs custom with a utilisation ROI. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
