The verdict in three sentences
A fibre subcontractor with 60 technicians completing 3,000 connections a month in Berlin and seeing 8% of its job reports rejected leaves a large slice of its cash stuck with network operators. A custom tracking app, with mandatory photos and quality checks and export to operator portals, costs between 35,000 and 80,000 EUR excl. VAT on the market (2026 estimate) for 3 to 4 months of development. The relevant calculation is not the software price, it is the number of payment days gained on every connection approved first time.
Why an 8% rejection rate is so expensive
Every FTTH connection produces a job report uploaded to the portal of the operator or wholesale network owner. A blurred photo of the termination box, a missing optical power reading or a wrong distribution point reference is enough to get the file rejected. The technician sometimes has to go back on site, and payment slips by a full billing cycle.
| Indicator (2026 order of magnitude) | Current situation | Target with the app |
|---|---|---|
| Monthly connections | 3,000 | 3,000 |
| Job report rejection rate | 8% | 2% |
| Rejected files per month | 240 | 60 |
| Average price paid per connection | 180 to 260 EUR excl. VAT | Same |
| Payment delay on a rejected file | 45 to 75 days | 30 days |
| Return visits for rework | 70 to 90 a month | 15 to 25 a month |
| Cost of a return visit (technician + van) | 90 to 140 EUR | Same, but rarer |
With 240 files at about 220 EUR, more than 52,000 EUR excl. VAT waits an extra cycle every month, before counting return visits.
What the field app must include
The heart of the project is a guided smartphone flow that stops the technician from closing an incomplete job. The back office then validates the file before export to the operator portal.
| Module | Function | Share of budget (estimate) |
|---|---|---|
| Guided flow per connection type | Mandatory steps, timestamps, geolocation | 20 to 25% |
| Photo quality control | Sharpness, framing, AI label detection | 15 to 20% |
| Optical measurement entry | Power meter import, alert thresholds | 10% |
| Validation back office | Review queue, rejection reasons, per-technician stats | 15 to 20% |
| Export to operator portals | Files in the expected format or API where available | 15 to 20% |
| Scheduling and dispatch | Customer appointments, routes, material stock | 10 to 15% |
Offline mode is essential: in basements and riser shafts, mobile coverage is often absent.
Market budgets and options
| Option (2026 market estimate) | Budget | Timeline | Main limitation |
|---|---|---|---|
| Generic no-code forms | 15 to 40 EUR per user per month | 2 to 4 weeks | No trade-specific quality control or operator export |
| Off-the-shelf field service software | 40 to 90 EUR per technician per month | 1 to 2 months | Operator portal adaptations billed separately |
| Custom app | 35,000 to 80,000 EUR excl. VAT | 3 to 4 months | Higher upfront investment |
| Maintenance of a custom app | 12 to 18% of budget per year | Ongoing | Must be planned from day one |
For 60 technicians, a market tool at 70 EUR a month adds up to 50,400 EUR over 12 months, with no code ownership and no control over the roadmap. Kolonell prices this kind of app within its custom application grid, quoted after scoping.
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Jonas, managing director of a telecom subcontractor in Berlin (illustrative scenario), bills 3,000 connections at 220 EUR excl. VAT. By cutting rejections from 8% to 2%, he avoids 180 pending files a month, or 39,600 EUR excl. VAT paid about 35 days earlier. At an overdraft cost of 6% a year, the financing saving is modest, but he also removes around 60 return visits at 110 EUR, or 6,600 EUR a month, and frees 60 technician half-days. On a 60,000 EUR project, break-even lands around 9 months, before counting the extra connections completed.
FAQ
Can the app upload files straight to operator portals?
It depends on the operator: some offer an API, others require standardised file uploads. In the second case, the app builds the full package in one click, bringing upload time under 2 minutes per file.
How does AI check the photos?
A model checks sharpness, label presence and framing before closure. On projects of this kind, 70 to 80% of photo rejections are blocked at source.
Do technicians need new smartphones?
No, a recent mid-range Android at 200 to 300 EUR is enough. Offline storage needs about 4 GB free for a week of jobs.
How long does it take to train 60 technicians?
Half a day per group of 10 is enough if the flow is well designed. A gradual rollout with a pilot team takes 2 to 3 weeks.
Who owns the data and the code?
The development contract provides for the transfer of rights and full data export. That matters if you switch prime contractor or supplier.
Let's scope your project. Tell us your monthly volume, your client operators and your main rejection reasons: we scope the perimeter, an indicative budget and a 3 to 4 month plan. Detailed quote within 48 h via our quote form. 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.
