The verdict in three sentences
Application maintenance is not optional: without it, your app degrades and fixes become emergencies billed at premium rates. The classic trap is confusing corrective work (included in the package) with evolutive work (billed separately): demand the contract settle this in black and white. In 2026, what truly protects you are quantified SLAs (response and resolution times) backed by penalties, not the vague promise of responsive support.
Maintenance contract model
A readable contract clearly separates what is covered from what is billed.
| Service | Corrective (package) | Evolutive (billed) |
|---|---|---|
| Blocking bug fix | included | - |
| Security update | included | - |
| Framework version upgrade | per contract | often billed |
| New feature | - | 400-600 EUR/day |
| Performance optimization | partial | additional |
| Level-2 user support | included | - |
| Typical annual budget | 8-20 % of project cost | on demand |
For an app delivered at 60,000 EUR, count on maintenance of 4,800 to 12,000 EUR/yr depending on commitment level.
The quantified SLA tiers
The SLA defines your contractual response times. Without numbers, it is worthless.
| Tier | Response time | Resolution time | Availability | On-call | Premium vs base |
|---|---|---|---|---|---|
| Basic | 8 business h | 3 business days | 99.0 % | no | baseline |
| Standard | 4 business h | 1 business day | 99.5 % | no | +25 % |
| Premium | 2 h (24/7) | 8 h | 99.9 % | yes | +60 % |
| Critical | 1 h (24/7) | 4 h | 99.95 % | yes + backup | +100 % |
Non-compliance penalties (often 5-10 % of the monthly fee per incident) are what give the SLA weight.
Mini case study
Marc, CFO of an e-commerce SME in Bordeaux, had his platform built for 80,000 EUR. A vendor offers pure time-and-materials maintenance at 550 EUR/day, unpredictable. He instead negotiates a fixed 12 % of project cost, i.e. 9,600 EUR/yr, covering fixes, security and 2 evolutive days per month, with a Standard SLA (1-day resolution). A blocking payment bug during the sales period is fixed in 6 hours: without an SLA, the estimated loss would have reached 15,000 EUR in revenue. The package pays for itself from the first incident avoided.
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FAQ
Fixed package or time-and-materials: which to choose?
The package secures your budget and suits predictable needs; T&M offers flexibility but makes spend volatile. The healthiest combination is a fixed corrective package plus an evolutive hours pool.
What exactly does the included corrective cover?
Bugs, security flaws and level-2 support. It does not cover new features or major version upgrades, which fall under billed evolutive work.
How much does maintenance cost in 2026?
Order of magnitude: 8 to 20 % of the initial development cost per year. A 60,000 EUR project thus implies 4,800 to 12,000 EUR of annual maintenance depending on the SLA.
Are SLA penalties really enforced?
Yes if they are quantified in the contract (for example 5 % of the monthly fee per hour of resolution delay). An SLA without penalties is an intention, not a commitment.
Do I need 24/7 on-call?
Only for a critical app (payment, health, continuous production). For an internal tool in business hours, a Standard SLA suffices and avoids the 60 % on-call premium.
Let's scope your project. Give us your application's cost, its criticality and your operating hours: we build a maintenance contract with quantified SLAs and penalties. 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.
