Collect existing evidence first
Start with engineering drawings, controller project files, switch configurations and maintenance records. Ask the line owner which sources are current. The initial task is reconciliation, not broad network probing. Record the source and date for every asset so an old spreadsheet does not silently become the source of truth.
Use a minimum useful record
Capture device role, location, owner, manufacturer, model, software version, network identifiers and operational dependency. Mark unverified fields explicitly. A guessed firmware version is less useful than an honest unknown with an assigned follow-up. Keep credentials out of the inventory and link to the approved credential-management process instead.
Reconcile with operations
Review one cell at a time with the people who maintain it. Identify devices whose failure stops the process, systems with no supported backup and interfaces shared with vendors. Any active discovery needs separate operational approval and a device-specific plan. Do not infer that a quiet address is unused.
Make updates part of change control
Add an inventory update to commissioning, replacement and retirement checklists. Track unresolved items with a person and a review date. A useful acceptance test is whether the team can identify the owner, backup and dependency of a selected critical device within the agreed response time.
Put it into practice
Use the related tool to check your assumptions, then bring the results to your project discussion.