The verdict in three sentences
An ERP connector that works today will eventually break, driven by version upgrades and API changes. Application maintenance (TMA) costs 12-20%/yr of build cost in 2026, i.e. a monthly retainer of EUR 400-1,800 depending on SLA. Not budgeting it means risking a data-flow outage that halts invoicing or logistics for several days.
What a connector maintenance contract covers
Maintenance isn't just a hotline. It combines corrective, preventive and evolutionary work, with a contracted service level. Here are the typical tiers in 2026.
| Tier | Monthly retainer | Fix SLA | Scope |
|---|---|---|---|
| Essential | EUR 400-700 | 24 business hrs | fixes, basic monitoring |
| Standard | EUR 700-1,200 | 8 business hrs | fix + preventive + alerting |
| Premium | EUR 1,200-1,800 | 4 business hrs | + on-call, enhancements included |
| Critical | on quote | < 2 h, 24/7 | vital flows, redundancy |
Monitoring and alerting are the heart of good maintenance: catching an API break before the business user prevents the outage from becoming a production incident.
Retainer vs time-and-materials: which to choose?
Two models coexist: a predictable monthly retainer or on-demand time-and-materials. The right choice depends on incident frequency and ERP upgrade cadence.
| Criterion | Monthly retainer | Time-and-materials |
|---|---|---|
| Budget predictability | high | low |
| Cost if few incidents | paid anyway | pay per use |
| Guaranteed SLA | yes | no |
| Applicable day rate | included | EUR 600-800/day |
| Suited if | critical flows | stable, low-use connectors |
An ERP integrator day rate is EUR 600-800 in 2026 (ballpark). On time-and-materials, an uncovered 2-day incident costs EUR 1,200-1,600, with no guaranteed turnaround.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Mini case study
Eric, CIO of an industrial SMB, had 3 ERP connectors built (bank, e-commerce, WMS) for EUR 45,000. Without maintenance, an ERP version upgrade breaks the WMS connector on a Monday morning: shipments are blocked for 3 days, estimated outage cost ~EUR 18,000 (delays, penalties, crisis hours). A Standard contract at EUR 950/month (EUR 11,400/yr, about 19% of the EUR 45,000 build but covering all 3 connectors) would have detected and fixed the break in under 8 hours. He signs a contract after the incident.
FAQ
Why is maintenance a percentage of the build? Because maintenance load is proportional to the complexity and number of connectors built. 12-20%/yr is the 2026 market range.
What happens during an ERP version upgrade? The ERP API can change and break a connector. Preventive maintenance tests and adapts connectors before the switch, avoiding a data-flow outage.
Is a retainer worth it if I have few incidents? For critical flows, yes: a single uncovered production incident (invoicing or logistics outage) often costs more than a year of retainer.
Is monitoring really useful? Yes, it's what separates reactive from proactive maintenance. Catching the outage before the user cuts recovery time by 5 to 10x.
Can I change SLA tier mid-contract? Yes, the SLA (24 h, 8 h, 4 h) adjusts to observed criticality. Many start in Standard, then move up when flows become vital.
Let's scope your project. Tell us the number of connectors, your ERP, its update cadence and your critical flows, and we'll price a maintenance contract at the right SLA. 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.
