Turning legacy shutdown into a governable transformation program

After several failed modernization attempts, the client faced the imperative to fully replace its legacy BSS landscape and migrate all customer segments to a new platform by a fixed deadline. The challenge went beyond technical migration: fragmented initiatives, limited capacity and high day‑to‑day operational pressure undermined transparency, prioritization and management control. Without a clear transformation target picture and an integrated portfolio steering logic, there was a material risk of local optimization, delivery overload and operational disruption. The core challenge was to regain end‑to‑end control over a multi‑year legacy shutdown while maintaining stable operations across private, SME and business customers.

We established a portfolio‑driven organizational transformation setup focused on governance, prioritization and execution control:

• Quarterly focus cycles: Structured management workshops to translate shutdown milestones into prioritized, executable portfolio packages, ensuring end‑to‑end coverage across business processes and customer segments
• Delivery governance & ways of working: Clear decision rules, feature freezes and active capacity steering (e.g. 70% build vs. 30% feedback) to protect operations while keeping transformation initiatives on the critical path
• End‑to‑end migration & cutover control: Integrated steering of migration waves, staged channel openings and cutover readiness, enabling management to actively control progress, risks and residual volumes instead of reacting ad hoc

The transformation created a consistent management framework for steering large‑scale migration under pressure. Critical topics were sequenced transparently across multiple portfolio cycles, aligning business and IT around shared priorities. New customer channels were successfully opened on the target platform while legacy channels were gradually decommissioned. Approximately 97% of the customer base – over 700,000 customers – were migrated with maintained processability, including full retail functionality. Beyond delivery outcomes, the client established a proven project and portfolio management model that enables controlled execution, informed decision‑making and sustainable transformation capability.

The client is a regional German telecommunications provider offering fixed, fibre, mobile and TV services to private and business customers. Operating in a highly competitive market with significant legacy constraints, it must continuously transform its organization while safeguarding operational stability and customer experience.