All case studies

Where reduction worked

Lumen Technologies

Retired about 50 mainframe applications and decommissioned about 90 switches

A telecom's modernisation programme powered down 4,500+ DSLAMs and retired mainframe apps on its way to $400M+ in exit run-rate savings.

Removed: about 50 mainframe applications, about 90 local and national switches, and more than 4,500 DSLAMs streamlined and powered down, inside a modernisation and simplification programme.

Outcome: the programme reported $400M+ of exit run-rate savings in FY25 against an original goal of $250M, with $700M planned on exit from 2026.

Lumen’s Q2 2026 corporate overview lists, under “How we have driven value-to-date”:

  • ~90 real estate site exits completed
  • ~90 local and national switches decommissioned
  • 4,500+ Digital Subscriber Line Access Multiplexers (DSLAM) streamlined, powered down
  • ~50 mainframe apps retired and 300+ apps migrated to the cloud
  • $100M+ AI-led or AI-enabled aEBITDA savings

The page is careful with its numbers, and the case should be too: the $400M+ figure is the programme’s total exit run-rate saving, and the deck does not say how much of it came from the retirements rather than the migration or the AI work. What it does say plainly is that a telecom retired its own copper-era estate — every switch and mainframe powered down is a system that no longer needs patching, monitoring or an owner.

Source: Lumen Technologies, Corporate Overview Deck Q2 2026 (undated deck, retrieved 24 October 2026)