When an experienced maintenance technician announces retirement, management often focuses on replacing the position.
That is only half the problem.
The new employee may have similar qualifications, but they will not know which machine loses communication after a power cut, which spare motor has the wrong encoder, which alarm message is misleading, or which supplier still repairs an obsolete drive.
A technician who has spent twenty years in one plant carries a private map of its weaknesses. Much of that knowledge was never written down because everyone simply knew whom to call.
Once that person leaves, small faults become long breakdowns. The goal is not to record everything they have ever learned. It is to capture the knowledge that would be expensive, dangerous, or time-consuming to rediscover.
Start Before the Final Week
Knowledge transfer should begin months before the technician leaves, not during their last two afternoons.
Create a list of critical machines and systems, then schedule short sessions around them. One focused hour beside a machine is usually more valuable than asking the technician to write a long general document from memory.
Record who will receive the knowledge. Ideally, the retiring technician should train at least two people rather than creating another single-person dependency.
Do not treat knowledge transfer as extra work to be completed between breakdowns. Give it scheduled time.
Identify the Machines Only They Understand
Ask a direct question:
Which machines would cause the biggest problems if you were unavailable tomorrow?
The answer may not match the most expensive equipment in the factory. A small labelling machine with obsolete controls may be harder to recover than a modern production line with strong supplier support.
For each critical machine, document:
- Normal startup and shutdown procedure
- Common breakdown symptoms
- Checks that should be performed first
- Known weak components
- Unusual interlocks
- Safe recovery after an interrupted cycle
- Required software and cables
- Available external support
Also ask which machines should not be restarted casually after a fault. Some equipment may require checking product position, valve states, temperatures, pressure, or mechanical alignment before continuing.
Capture Failure Patterns
Maintenance systems record individual work orders. Experienced technicians remember patterns across years.
Ask questions such as:
- Which faults return regularly?
- Which alarms usually point to the wrong cause?
- What tends to fail after a long shutdown?
- Which problems appear only in hot or cold weather?
- Which faults occur after cleaning or product changeovers?
- Which components fail gradually rather than suddenly?
- Where do operators commonly make mistakes?
Record the symptom, likely causes, diagnostic checks, and confirmed repair.
Avoid vague notes such as “Machine sometimes has sensor problems.” A useful entry would say that a particular conveyor stops intermittently because oil contamination weakens the photoelectric sensor signal, and that cleaning the reflector should be checked before replacing the PLC input module.
This type of detail can save hours of unnecessary troubleshooting.
Find Every Program and Backup
The retiring technician may know where the real PLC, HMI, robot, drive, and safety-controller backups are stored.
Do not accept a folder containing files named Final, Final2, and Final_New.
For every control system, verify:
- Controller model and firmware
- Programming software and version
- Latest working project
- Date the backup was verified
- Whether the online program matches the saved version
- HMI and SCADA project files
- Drive and servo parameters
- Robot backups
- Safety-program access procedure
- Required licences and adapters
Store the files in approved company storage with controlled access and backups. Do not leave the only copy on the retiring technician’s laptop.
Passwords, licence credentials, and privileged access should be transferred through the company’s approved secure process. They should not be written on a noticeboard or placed in an unprotected spreadsheet.
Extract the Unwritten Modifications
Many plants contain years of temporary fixes, discontinued features, hidden bypasses, and modifications that never reached the drawings.
Ask the technician to identify:
- Disconnected sensors
- Unused cables
- Temporary jumpers
- Modified safety circuits
- Disabled alarms
- Spare PLC inputs and outputs
- Changed motor or gearbox sizes
- Replacement components with different specifications
- Program changes not shown in drawings
- Equipment operating outside its original design
Every questionable modification should be reviewed, not simply preserved because “it has always worked.”
Safety-related changes deserve immediate attention from appropriately qualified personnel. Knowledge transfer must not become an excuse to continue an unsafe condition.
Update electrical drawings, I/O lists, panel layouts, network diagrams, and parts lists while the technician is still available to explain discrepancies.
Review the Spare Parts Reality
The maintenance database may say that a spare exists. The retiring technician may know that it is faulty, incomplete, or intended for another machine.
Physically inspect critical spares together.
Confirm:
- Exact part number
- Which machine uses it
- Whether it has been tested
- Required firmware or configuration
- Missing connectors or accessories
- Storage location
- Reorder lead time
- Approved replacement model
Ask which obsolete parts are becoming difficult to source and which suppliers are trustworthy.
A dusty PLC on a shelf is not a useful spare if it contains the wrong program, requires unavailable software, or failed when it was removed.
Capture Supplier and Contractor Knowledge
Experienced technicians often know who actually answers the phone when a machine stops.
Create a contact list containing:
- Machine builder
- Local integrator
- Electrical contractor
- Motor and gearbox repair shop
- PLC and drive supplier
- Instrumentation specialist
- Refrigeration or hydraulic support
- After-hours contacts
- Support contract details
Record what each supplier is good at. One contractor may be excellent with old Siemens systems but weak with robots. Another may respond quickly but require accurate part numbers before visiting.
Where possible, introduce the replacement technician to important external contacts before retirement.
Ask Them to Demonstrate, Not Just Explain
People frequently omit steps when describing tasks they have performed for years.
Have the technician demonstrate important procedures while another employee performs them under supervision.
Useful demonstrations include:
- Restoring a PLC or HMI backup
- Replacing and configuring a VFD
- Recovering a machine after power loss
- Calibrating a critical instrument
- Aligning a difficult sensor
- Changing a product recipe
- Restarting after an emergency stop
- Testing an intermittent fault
Record short internal videos where company policy allows it. A five-minute video showing a difficult calibration can be more useful than several pages of text.
Ask the Questions People Usually Avoid
Near the end of the handover, ask:
What are you worried will happen after you leave?
Also ask:
Which problems has management postponed for too long?
Experienced technicians often know about fragile systems, unsupported software, overloaded components, poor-quality repairs, or machines that are one failure away from extended downtime.
These answers may be uncomfortable, but they are often the most valuable part of the handover.
Turn Knowledge Into a System
Do not create one enormous document nobody will open.
Organise the information by machine and make it searchable. Each machine should have a small package containing drawings, backups, parts, contacts, known faults, recovery procedures, and maintenance history.
Assign an owner to update the information after retirement. Otherwise, the handover becomes outdated almost immediately.
The retiring technician’s greatest value is not a list of secret tricks. It is the context behind years of faults, repairs, modifications, and production pressure.
Capture that context early. Verify it on the actual equipment. Transfer it to several people. Then convert it into documentation the plant can continue using.
A retirement date should mark the end of one person’s employment—not the disappearance of the factory’s technical memory.