Werk 05 — who carries it
Legacy work is a cost and risk argument before it is a technology argument. The estate is expensive, slow to change and load-bearing, and the only acceptable exit is one that never takes the business offline.
The offer
A fixed-cost legacy estate moved onto modern infrastructure while the business keeps running — with the decommissioning actually done, not deferred.
Application-by-application disposition — rehost, replatform, refactor, rewrite, retire — with cost, risk and sequencing.
z/OS or AS/400 exit path, workload migration, batch-to-event conversion and the parallel-run strategy that de-risks cutover.
Strangler pattern applied domain by domain, with the seams, the routing layer and the data separation planned before code moves.
DB2 and VSAM migration, reconciliation controls, and the formal shutdown that releases the run cost.
Estate inventory, 7R disposition, cutover plan, TCO model.
Migration architecture owned, risk arbitrated, vendors held to it.
The exit executed, the legacy platform switched off.
State of the proof
Experiences that prove it
Sub-capabilities and evidence
Publishable figures
Questions
- What does a legacy mandate actually move?
- The applications and their economics together. At PMU the total cost of ownership of the replatformed betting applications fell 87% and change lead time fell 41%, while the availability target held.
- What is declared rather than proven here?
- COBOL and 4GL modernization, batch-to-event migration, legacy data migration and green-screen UX are in scope for a mandate and no published case carries them. They are listed as declared rather than dropped, because the estate that needs them is the estate this werk exists for.
- Why is a legacy estate a board problem?
- Because it prices every other decision. A fixed-cost mainframe sets the floor under the IT budget, and long lead times set the ceiling on how fast the business can answer a competitor. At PMU both moved in the same mandate: cost of ownership down 87%, change lead time down 41%.
- Does modernization mean rewriting?
- Rarely, and never by default. Adeo's gain came from decommissioning rather than rebuilding — dismantling legacy systems released EUR 9.5M. The 7R decision is made per application against its remaining life, not per estate against a slogan.