The verdict in three sentences
A multi-subsidiary group faces a structuring trade-off: multiply independent sites or unify on a shared platform. The unified platform, with a shared design system and multi-space CMS, costs more upfront but cuts cumulative maintenance costs by 40 % and guarantees brand consistency. Budget 70 000 to 230 000 EUR depending on the number of subsidiaries and the degree of editorial autonomy.
The architecture scenarios compared
2026 orders of magnitude for a group of 4 to 8 subsidiaries in a European market.
| Scenario | Upfront investment | Maintenance/year | Brand consistency | Subsidiary autonomy |
|---|---|---|---|---|
| Independent sites | 45 000 - 100 000 | 26 000 - 52 000 | Low | Total |
| Templated multi-site | 80 000 - 145 000 | 20 000 - 35 000 | Medium | High |
| Unified platform | 125 000 - 230 000 | 16 000 - 28 000 | Strong | Framed |
| Hub + satellites | 100 000 - 180 000 | 18 000 - 30 000 | Strong | Modular |
Over a 3-year cycle, the unified platform and the hub + satellites model become clearly cheaper than independent sites, while professionalising governance.
The 3-year total cost and savings levers
TCO (total cost of ownership) is the right metric for a group CIO, not upfront cost alone.
| Line item | Independent sites (3 yrs) | Unified platform (3 yrs) |
|---|---|---|
| Upfront investment | 72 000 | 165 000 |
| Cumulative maintenance | 117 000 | 66 000 |
| Enhancements & security | 50 000 | 27 000 |
| CMS licences | 20 000 | 13 000 |
| Total 3 years | 259 000 | 271 000 |
TCO converges by year 3, then the unified platform becomes clearly cheaper from year 4 (-40 % cumulative maintenance). The levers: shared design system, reusable components, multi-space CMS with roles, and pooled security deployment.
Mini case study
Thomas, CIO of a European industrial group with 6 subsidiaries, today manages 6 disparate sites, 3 vendors and 44 000 EUR/year of scattered maintenance. He chooses a unified platform at 160 000 EUR, delivered in 7 months, with a shared design system and a 6-space CMS. From year 2, his maintenance drops to 24 000 EUR/year. Over 4 years, cumulative maintenance savings reach around 82 000 EUR, not counting brand consistency gains and the reduction in time to launch a new subsidiary, down from 3 months to 3 weeks.
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FAQ
Do all subsidiaries need a single CMS?
A multi-space (multi-tenant) CMS lets each subsidiary manage its content autonomously while sharing components and security. It is the best compromise between consistency and agility for a group.
Does a shared design system constrain subsidiaries?
No: it sets the foundations (grid, components, accessibility) but allows per-subsidiary variations (colours, imagery). You frame without uniformising, which speeds up each new site.
How long to deploy a new subsidiary on the platform?
With a mature unified platform, 2 to 4 weeks versus 2 to 3 months for a standalone site. It is one of the most tangible gains for a growing group.
How do we handle multilingual at group scale?
Centralise the i18n logic in the platform and let each subsidiary translate its content. Add 8 to 15 % to budget depending on the number of languages and RTL support.
What is the ROI of unification?
Usually reached between year 3 and 4, via lower maintenance (-40 %), pooled enhancements and faster time-to-market for new sites.
Let's scope your project. Tell us the number of subsidiaries, languages, desired autonomy level and indicative budget: we model the architecture scenario with the best TCO. 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.
