The verdict in three sentences
An HR consulting firm wins or loses on a single figure: its consultant utilisation rate. A market PSA (30-70 EUR per user/month) steers the standard; a custom build of 45,000 to 100,000 EUR pays off for granular utilisation tracking, custom time billing and an integrated candidate portal. The return is measured in utilisation points gained, not licence saved.
Build, Odoo or vertical PSA: the real trade-off
The criterion is not the monthly price but the precision of profitability steering. 2026 orders of magnitude for a 20-consultant firm.
| Item | Vertical PSA | Configured Odoo/ERP | Custom |
|---|---|---|---|
| Licence/user/month | 30-70 EUR | 15-40 EUR | 0 + hosting |
| Annual cost, 20 users | 7,200-16,800 EUR | 3,600-9,600 EUR | 2,400-6,000 EUR |
| Utilisation tracking | Standard | To configure | Custom, real time |
| Time billing | Yes | Add-on module | Full (time, fixed, T&M) |
| Candidate portal | Rare | No | Integrated |
| Staffing customisation | Low | Medium | Full |
| Initial development | 3,000-10,000 EUR | 15,000-40,000 EUR | 45,000-100,000 EUR |
Over three years, the PSA for 20 consultants costs 22,000 to 50,000 EUR. The custom build pays back once utilisation gains a few points — which counts heavily, see below.
The ROI: utilisation and administrative time
The two financial levers of a consulting firm.
| Metric | Before PSA | After custom |
|---|---|---|
| Consultant utilisation | Baseline | +8 to 12 points |
| Administrative time | Baseline | -20% |
| Engagements billed late | 10-15% | < 5% |
| 4-week staffing visibility | Low | Full |
| Billing lead time | 30-45 days | 15-25 days |
For a 20-consultant firm billed on average 550 EUR/day, gaining 10 utilisation points = 10 extra billed days per consultant per year = 200 days × 550 EUR = 110,000 EUR of additional revenue.
Mini case study
Sophie, head of a 20-consultant HR firm in Paris, plateaued at 68% utilisation. Investment: a custom build at 72,000 EUR with real-time utilisation tracking, time billing and a candidate portal. Estimated gain: +9 utilisation points = 9 extra billed days per consultant across 20 consultants at 550 EUR = 99,000 EUR/year of additional revenue, plus -20% administrative time. The investment pays back in under 9 months.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
FAQ
Should you go custom or configure Odoo?
Configured Odoo (15,000-40,000 EUR) covers firms with standard processes. Custom (45,000-100,000 EUR) pays off when profitability steering, staffing and billing follow rules specific to your firm that standard modules model poorly.
How is the utilisation gain calculated?
Each utilisation point gained equals about 2 extra billed days per consultant per year. At 550 EUR/day and 20 consultants, 10 points are worth nearly 110,000 EUR of revenue — hence the fast payback.
Is a candidate portal useful for an HR firm?
Yes for recruitment-heavy firms: it centralises applications, interviews and follow-up, and feeds engagements directly. It avoids double entry between the ATS and the engagement-management tool.
How long to deploy?
Between 12 and 18 weeks for a custom build including utilisation tracking, billing and migration of ongoing engagements. A PSA deploys in 5 to 8 weeks.
Can time tracking link to billing?
Yes, that is the core benefit: time entered by consultants feeds time billing automatically, cutting the lead time from 30-45 days to 15-25 days and late-billed engagements below 5%.
Let's scope your project. Tell us your number of consultants, current utilisation and priorities (utilisation, billing, candidate portal) for an indicative budget between 45,000 and 90,000 EUR. 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.
