The verdict in three sentences
For a multi-trade maintenance company in Lille with 45 technicians on 24/7 on-call duty, off-the-shelf rota software costs 8 to 15 EUR per user per month, or 4,300 to 8,100 EUR a year, while a custom app requires 20,000 to 40,000 EUR upfront, excluding VAT. A custom build makes sense when you must automate the French Labour Code precisely (11-hour rest, on-call compensation, call-outs counted as working time) and push on-call allowances into payroll with no re-keying. The target gain: 6 hours of scheduling saved per week and payroll disputes cut by 4.
The rules the tool must apply without error
On-call duty is governed by articles L3121-9 onwards of the French Labour Code. The employee stays reachable without being at the workplace; the on-call period must be compensated with money or time off; only the call-out duration counts as working time. The 11 consecutive hours of daily rest and 35 hours of weekly rest still apply, which complicates scheduling when a technician is called out at 3 a.m. and must start again at 8 a.m. Individual schedules must in principle be shared 15 days in advance, unless a collective agreement sets another notice period.
| 2026 rule | Reference | What the tool must do |
|---|---|---|
| On-call compensation | Art. L3121-9 | Compute the allowance or time off per company agreement |
| Call-out = working time | Art. L3121-9 | Count real duration and night or Sunday premiums |
| 11-hour daily rest | Art. L3131-1 | Block a shift starting too soon after a call-out |
| 35-hour weekly rest | Art. L3132-2 | Alert if an on-call week breaks weekly rest |
| Notice period | Art. L3121-12 | Publish the rota 15 days ahead, log changes |
| 48-hour weekly maximum | Art. L3121-20 | Add call-outs to normal hours |
| Monthly summary document | Art. R3121-2 | Produce an on-call statement per employee |
Off-the-shelf or custom: the costed comparison
SaaS rota tools handle simple rotations and shift swaps between colleagues well. They hit limits on three points: rules specific to your company agreement (different allowances by qualification or client site), integration with your CMMS and work orders, and payroll export in the exact format of your software (Silae, Sage, Cegid).
| Criterion | SaaS rota software | Custom app |
|---|---|---|
| Upfront cost | 0 to 3,000 EUR configuration | 20,000 to 40,000 EUR |
| Recurring cost for 45 technicians | 4,300 to 8,100 EUR per year | 2,400 to 4,800 EUR per year maintenance |
| Company agreement rules | Partial, standard settings | Coded exactly |
| Link with CMMS and work orders | Often missing or via export | Call-outs pulled automatically |
| Payroll export (Silae, Sage, Cegid) | Generic file to rework | Payroll variables in exact format |
| Time to go live | 2 to 6 weeks | 3 to 4 months |
| Cumulative 5-year cost | 21,500 to 43,500 EUR | 32,000 to 64,000 EUR |
Over 5 years, SaaS remains cheaper. The custom build pays off through time saved and payroll errors avoided, not through licence savings.
What a custom app includes
A rotation calendar with fair distribution of weekends and public holidays, a mobile app where technicians accept their on-call slot, log call-outs and swap a slot with manager approval, a rules engine that rejects non-compliant rotas, and a monthly export of allowances and premium hours to payroll. Call-out data comes from the CMMS to avoid double entry.
Mini case study
Julien, operations manager of a multi-trade maintenance company in Lille, spends 8 hours a week building and fixing on-call rotas for 45 technicians. Payroll handles an average of 12 allowance complaints per month, at 1 hour each. With a custom app at 30,000 EUR and 300 EUR per month of maintenance, he drops to 2 hours of scheduling per week (6 hours saved) and 3 complaints per month. Time freed: 6 x 46 weeks = 276 hours, plus 108 payroll hours, or 384 hours. At a loaded hourly cost of 45 EUR, the gain reaches 17,300 EUR per year. Payback in about 2 years, excluding reduced employment tribunal risk.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
FAQ
How much does a custom on-call scheduling app cost in 2026?
Between 20,000 and 40,000 EUR excluding VAT depending on the number of rules, CMMS integration and payroll export, plus 200 to 400 EUR per month for maintenance.
Can a SaaS tool be enough?
Yes, for fewer than 20 technicians with standard rules. At 8 to 15 EUR per user per month, it deploys fast but handles specific company agreements poorly.
How does the tool enforce the 11-hour rest rule?
The rules engine compares the end time of each call-out with the next shift start and blocks or alerts if the gap is under 11 hours.
Can on-call allowances go straight to payroll?
Yes, the app generates monthly variables in Silae, Sage or Cegid format. That is what cuts complaints by 4.
How long does development take?
Three to four months, including 3 weeks to formalise rules with HR and 4 weeks of testing alongside the old rota.
Let's scope your project. Describe your teams, your on-call agreement and your CMMS and payroll tools: we will price a scheduling app between 20,000 and 40,000 EUR, delivered in 3 to 4 months. 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.
