Work · PM · TPM
The Light Test
A circuit that had been running for over a decade, untouched, wasn't in any database. It failed a migration twice before we stopped diagnosing it remotely and traced the fibre ourselves.
- Result
- New standard step
- Role
- Technical Programme Manager, Vodafone (via Interactive Management Solutions)
- When
- 2019–present
The circuit that existed nowhere
Inside the decommissioning programme, one circuit ran from the exchange to a lab building. It wasn’t recorded anywhere, and nothing on it had been touched in over a decade.
Two wrong guesses
The first migration attempt failed. The working theory was a faulty optical transceiver, so we replaced it. Same failure. That was the point we accepted the hypothesis was wrong, not the execution.
Going to look
We stopped diagnosing it remotely and traced the fibre ourselves, physically, between the two buildings. A specialist contractor completed new patching, and we ran the migration overnight from the exchange itself.
What changed afterwards
- The migration completed.
- We added an end-to-end light test as a standard step, to prove the physical path before every future migration, regardless of what any database said.
- The circuit itself was added to the network inventory, so it existed in the records from then on.
Result
The programme that fed this work (see The £6M Thread Pull) had already verified every link three ways: traffic monitoring, inventory records, and service-owner confirmation. All three assume the circuit is recorded somewhere. This one wasn’t, and no amount of rigour on the existing process would have caught that. The gap needed a fourth check: go and look.
All three verification methods trusted a record that didn’t exist. The fix was standing at the exchange, not another database check.