The Challenge
A 200-location retail chain was running its core infrastructure from two ageing on-premises data centres approaching end-of-life. Refresh would cost an estimated £3.8M. The board wanted to explore cloud migration as an alternative — but had concerns about risk, complexity, and total cost of ownership.
Our Approach
We began with a 6-week discovery phase: a full workload inventory, TCO analysis, and a risk-tiered migration roadmap. We identified 140 distinct workloads across the estate, categorising each by migration complexity and business criticality.
The migration ran in eight waves over six months, starting with non-critical workloads to build confidence and refine the operating model before tackling production systems. All migrations used a blue-green deployment approach with automated rollback. The retail ERP — the highest-risk workload — was migrated in the final wave with a 72-hour parallel run period.
The Results
- 34% reduction in infrastructure cost vs. data centre refresh alternative
- 99.97% uptime in the first 12 months post-migration
- Mean recovery time from incidents reduced by 76% (cloud automation vs. manual data centre response)
- On-premises data centre fully decommissioned on schedule