The verdict in three sentences
A 12 to 20 page requirements document is enough to get a business web application seriously quoted, provided it describes user roles, 15 to 30 prioritised user stories, integrations and data volumes. Without it, the quotes an SME in Dublin receives vary by a factor of 3; with it, the gap drops to 1.4. For a scheduling application, budget EUR 30,000 to 70,000 excluding VAT and 4 months of development.
The 7 sections of a usable requirements document
An operations director does not need to write technical specifications. They need to describe the business need precisely enough for three agencies to quote the same thing.
| Section | Expected content | Indicative size | Impact on the quote |
|---|---|---|---|
| Context and goals | Current problem, 3 measurable success indicators | 1 page | Frames the project's value |
| User roles | Planner, team lead, technician, management | 4 to 6 roles | Defines access rights |
| Prioritised user stories | "As a... I want... so that...", ranked MoSCoW | 15 to 30 stories | 60% of the estimate |
| Integrations | ERP, payroll, Outlook calendar, SSO | 2 to 4 systems | 15 to 30% of the budget |
| Data volumes | Users, schedules per day, history | 1 table | Sizes the hosting |
| GDPR requirements | Personal data, retention period, EU hosting | 1 page | Shapes the architecture |
| Constraints | Deadline, budget cap, browsers, mobile | Half a page | Avoids surprises |
The most underestimated section is data volume. An application managing 40 employees and 200 slots a week has nothing in common with a tool for 400 employees across 6 sites. Stating these figures stops the agency from over-sizing out of caution, which inflates the quote by 20 to 30%.
With or without requirements: the real quote gap
We compared the ranges observed on scheduling application projects in 2026 (2026 order of magnitude).
| Indicator | Without requirements | With structured requirements |
|---|---|---|
| Gap between lowest and highest quote | 1 to 3 (EUR 25,000 to 75,000) | 1 to 1.4 (EUR 45,000 to 63,000) |
| Back-and-forth before a firm quote | 4 to 6 meetings | 1 to 2 meetings |
| Time to get 3 comparable quotes | 6 to 8 weeks | 2 to 3 weeks |
| Average budget overrun at project end | 25 to 40% | 5 to 12% |
| Contract change orders | 3 to 5 | 0 to 1 |
| Billed discovery phase | 10 to 15 days | 3 to 5 days |
The lowest quote without requirements often ends up the most expensive: the agency priced the minimum and then bills every omission as a change order.
Typical budget and schedule for a scheduling application
| Work package | Scope | Budget excl. VAT | Duration |
|---|---|---|---|
| Discovery and mock-ups | Workshops, user journeys, approved Figma mock-ups | EUR 4,000 to 8,000 | 3 weeks |
| Technical foundation | Authentication, roles, back office | EUR 6,000 to 12,000 | 3 weeks |
| Scheduling and assignments | Drag and drop, conflicts, leave | EUR 10,000 to 25,000 | 6 weeks |
| Integrations | ERP, payroll, Outlook | EUR 5,000 to 15,000 | 3 weeks |
| Testing, acceptance, go-live | Automated tests, training | EUR 3,000 to 7,000 | 2 weeks |
| Annual maintenance | Fixes, EU hosting, minor changes | 15 to 20% of build per year | Ongoing |
Over 4 months, the critical path runs through integrations: late access to the ERP API pushes go-live back by 3 to 5 weeks. State in the requirements who provides access and by when.
Mini case study
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Thomas, operations director of an industrial cleaning SME in Dublin (85 staff, 3 planners), manages schedules in Excel. Each planner spends 12 hours a week rebuilding teams, i.e. 36 hours a week at EUR 32 fully loaded per hour: about EUR 55,000 a year.
He writes a 16-page requirements document with 22 user stories. The three quotes received range from EUR 48,000 to 64,000. He picks an offer at EUR 54,000. The application cuts scheduling time by 60%, saving EUR 33,000 a year. Payback: 20 months, including EUR 9,000 a year of maintenance.
FAQ
How long does it take to write a requirements document?
Allow 5 to 10 working days spread over 3 to 4 weeks, with 2 or 3 workshops involving future users. Agency support for this phase costs EUR 3,000 to 6,000.
Should we write the user stories ourselves?
Yes for the business substance, since only you know your scheduling rules. The agency then rephrases them and adds acceptance criteria, which takes 2 to 3 days.
What should the GDPR section contain?
The list of personal data processed, its retention period (often 3 years after an employee leaves) and a requirement for hosting within the European Union. Also plan an updated record of processing activities.
Can we ask for a fixed price rather than time and materials?
With precise requirements, yes: 70% of agencies accept a fixed price per work package. Without them, most impose time and materials at EUR 550 to 750 per day.
What if the need changes mid-project?
Keep a reserve of 10 to 15% of the budget for adjustments. An added user story costs EUR 1,500 to 4,000 on average depending on complexity.
Let's scope your project. Send us your requirements or first notes: we define scope, indicative budget and schedule in one workshop. 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.
