The verdict in three sentences
A distributor handling thousands of SKUs pays dearly for every picking error and every poorly optimized picking hour. A custom WMS (locations, guided picking, cycle counting, barcode scanning, ERP integration) costs 55,000 to 130,000 EUR over 18 to 28 weeks, versus 30 to 90 EUR per user per month for SaaS. From 15 operators, custom becomes profitable in under 3 years while fitting your exact warehouse logic.
Cost per module of a custom WMS
A WMS is built brick by brick. Here is a 2026 order of magnitude for a mid-size distribution warehouse.
| Module | Scope | Estimated build cost |
|---|---|---|
| Receiving & put-away | control, locations, ADR | 9,000 to 18,000 EUR |
| Guided picking + scanners | scan, sequencing, waves | 14,000 to 28,000 EUR |
| Cycle counting | periodic counts, variances | 7,000 to 14,000 EUR |
| Packing & shipping | cartonization, labels, EDI | 9,000 to 20,000 EUR |
| ERP / TMS integration | API, real-time stock sync | 8,000 to 18,000 EUR |
| Dashboards & KPIs | service rate, productivity | 6,000 to 12,000 EUR |
The core value stays in guided picking: it transforms productivity and slashes errors.
SaaS WMS vs custom WMS over 4 years
| Criterion (20 operators) | SaaS WMS | Custom WMS |
|---|---|---|
| Initial build | 0 EUR | 55,000 to 130,000 EUR |
| Subscription / operator / month | 30 to 90 EUR | 0 EUR |
| Annual subscription 20 seats | 7,200 to 21,600 EUR | 0 EUR |
| Hosting & maintenance / year | included | 7,000 to 14,000 EUR |
| Fit to your processes | limited | total |
| 4-year total | 29,000 to 86,000 EUR | 83,000 to 186,000 EUR |
SaaS stays cheaper in pure cash over 4 years at this seat count, but custom is justified once your processes are atypical and the operational gains below exceed the gap.
The operational gains that change the math
| Indicator | Before | After custom WMS |
|---|---|---|
| Service rate | 92% | 98% (+6 pts) |
| Picking errors | 1.8% | 0.9% (-50%) |
| Picking productivity | base 100 | 120 (+20%) |
| Inventory time | 3 days | 0.5 day |
| Client disputes / month | 40 | 18 |
On a warehouse shipping 60,000 lines per month, halving errors saves thousands of euros in returns and rebuilds B2B customer trust.
Mini case study
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Nadia, logistics manager at a spare-parts distributor in Lille, handles 18,000 SKUs and 20 pickers. Her 1.8% picking errors on 60,000 lines/month generate about 1,080 wrong lines monthly, each costing ~22 EUR (return, re-picking, credit note), i.e. 23,760 EUR/month of non-quality. A custom WMS at 95,000 EUR (amortized over 4 years = 23,750 EUR/year) plus 10,000 EUR of hosting halves those errors: she recovers ~11,880 EUR per month, over 142,000 EUR per year. The build is repaid in under 9 months by error reduction alone.
FAQ
How long to deploy a custom WMS?
Between 18 and 28 weeks. Start with receiving and picking (10-12 weeks), then counting, shipping and ERP integration. A pilot on one warehouse zone can run from week 12.
Do we have to replace our scanners and printers?
Not necessarily. A custom WMS adapts to most existing Android terminals and Zebra printers. If your fleet is obsolete, budget 300 to 700 EUR per rugged scanner.
How does ERP integration work?
Via API or EDI, with real-time stock synchronization. Cost ranges 8,000 to 18,000 EUR depending on whether your ERP exposes a modern API or requires file exchanges.
Is there a fallback mode if the network fails?
Yes, a good WMS embeds an offline mode on scanners: scans are queued and synced as soon as the network returns, so a shipment is never blocked.
Can we start small then expand?
Absolutely. Many distributors launch guided picking alone, measure the gains, then fund the next modules with the savings achieved.
Let's scope your project. Tell us your SKU count, operator count and current ERP: we will price a custom WMS, build 55,000 to 130,000 EUR, picking pilot from week 12. 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.
