The verdict in three sentences
A paid discovery phase before launching a business application protects an 80,000 EUR estimate from drifting toward 120,000 EUR. Budget 5 to 12% of the total, i.e. 4,000 to 12,000 EUR excl. VAT, over 3 to 6 weeks, to get user stories, mockups, a data model and a firm estimate. Insist on ownership of the deliverables: you must be able to consult another supplier with the same file.
Why projects without discovery overrun
An SME IT director who receives three quotes between 60,000 and 110,000 EUR for the same application has a simple problem: each supplier imagined a different application. Without detailed specifications, business rules are discovered during development, screens are rebuilt, and integrations (ERP, accounting, SSO) are underestimated. Budget overruns on such projects commonly range from 30 to 60%, as an order of magnitude, with delays of 2 to 4 months.
| Situation | Without discovery | With discovery |
|---|---|---|
| Gap between competing quotes | 40 to 80% | 10 to 20% |
| Budget drift at project end | 30 to 60% | 5 to 15% |
| Average go-live delay | 2 to 4 months | 0 to 1 month |
| Billed change requests | 15 to 30 | 3 to 8 |
| Screens rebuilt after acceptance testing | 20 to 35% | under 10% |
| Ability to switch supplier | Low | High, reusable file |
What a specification file must contain
The real test of discovery is whether a developer who never attended the workshops can estimate and build the application without coming back with twenty questions.
| Deliverable | Expected content | Share of effort | Indicative cost (80,000 EUR project) |
|---|---|---|---|
| Workshops and process mapping | 4 to 8 workshops, current and target processes | 20% | 1,200 to 2,400 EUR excl. VAT |
| User stories and acceptance criteria | 60 to 150 prioritised stories (MoSCoW) | 25% | 1,500 to 3,000 EUR excl. VAT |
| Interactive mockups | 15 to 40 clickable screens, tested by 3 to 5 users | 25% | 1,500 to 3,000 EUR excl. VAT |
| Data model | Entities, relations, volumes, retention rules | 10% | 600 to 1,200 EUR excl. VAT |
| Architecture and integrations | ERP flows, APIs, SSO, hosting, security | 10% | 600 to 1,200 EUR excl. VAT |
| Firm estimate and schedule | Lots, milestones, fixed price or 10% range | 10% | 600 to 1,200 EUR excl. VAT |
For an 80,000 EUR project, a discovery phase of 6,000 to 9,000 EUR excl. VAT over 4 weeks is the most common case. It drops toward 4,000 EUR when the scope is already well documented internally, and rises toward 12,000 EUR when the application spans several departments, sites or regulatory constraints (traceability, GDPR, health data).
Contract: three clauses to require
First, assignment of rights to all deliverables (documents, mockups, data model) upon payment for discovery. Second, a firm estimate at the end of the phase, with the supplier committing not to exceed a 10% range on the described scope. Third, deductibility: many agencies credit part or all of the discovery fee against development if you continue with them, often 50 to 100% of the amount. That brings the real cost of discovery close to zero if the project goes ahead.
On scheduling, plan for your key users' availability: 2 to 4 half-days each over the period. Discovery without business users produces specifications written by IT people for IT people.
Mini case study
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Claire Morel, IT director of a 140-employee distribution SME near Nantes, must replace a supplier returns tool built on spreadsheets. Initial quotes range from 65,000 to 105,000 EUR. She orders a 7,500 EUR excl. VAT discovery over 4 weeks. The file reveals two unplanned integrations (ERP and carrier) and also allows 30% of features to be moved to phase 2. Firm estimate: 78,000 EUR excl. VAT, delivered at 82,000 EUR, a 5% gap. Without discovery, with a 40% drift on the median estimate of 85,000 EUR, the project would have cost about 119,000 EUR. Net saving: nearly 29,500 EUR after deducting the discovery fee.
FAQ
How much does a discovery phase for a business app cost in 2026?
Usually 5 to 12% of the development budget, i.e. 4,000 to 12,000 EUR excl. VAT for an 80,000 EUR project. The amount depends on the number of departments involved and on integrations.
How long does discovery take?
From 3 to 6 weeks. Beyond 6 weeks, the scope is probably too broad and should be split into lots.
Can I give development to another supplier?
Yes, provided the contract includes assignment of rights to the deliverables. A good file yields quotes comparable within 10 to 20%.
Is discovery deducted from the development price?
Often, yes: many agencies credit 50 to 100% of it if you continue with them. Get it written explicitly into the purchase order.
What if the firm estimate exceeds my budget?
That is exactly what discovery is for: user stories are prioritised and 20 to 40% of features are moved to phase 2 to stay within the initial envelope.
Let's scope your project. Describe the target application, the departments involved and your indicative budget: we will propose a fixed-price discovery of 3 to 6 weeks with a firm estimate. 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.
