Last updated: 15 November 2026
What a retrofit is
Conveyor frames, racking and crane structures last for decades. Control systems, drives and software age much faster: components are discontinued, spare parts become scarce and the software no longer runs on current operating systems. A retrofit renews these parts and keeps the mechanical equipment, so the system gains a further service life at lower cost and in less time than a new installation.
Signs that a system needs modernization
- The manufacturer has discontinued the PLC, the drives or the operator panels, and spare parts are hard to find.
- Faults occur more often and take longer to diagnose.
- The visualisation or control software runs on an operating system that is no longer supported.
- The system cannot be connected to a new WMS or ERP, or new requirements cannot be implemented.
- Only a few people still know the system, and documentation is incomplete.
- Safety equipment no longer meets current standards.
What is renewed
- PLC and control cabinets: migration to a current controller generation, with new or adapted cabinets.
- Drives: frequency converters and motors where required, which also improves energy use.
- Sensors, scanners and positioning systems.
- HMI and SCADA: new operator panels and visualisation with clear fault diagnostics.
- Control and warehouse control software, including the interface to the WMS or ERP.
- Safety technology and network infrastructure.
Mechanical parts are inspected as well. Worn components such as belts, rollers, chains and wheels are replaced as part of the project where needed.
Retrofit or new system
| Situation | Retrofit | New system |
|---|---|---|
| Mechanical structure | In good condition | Worn or damaged |
| Capacity and layout | Still fit the operation | No longer sufficient |
| Product range | Largely unchanged | Changed fundamentally |
| Available downtime | Short windows only | A longer shutdown or a new building is possible |
Many projects combine both: the existing system is modernized and extended with new equipment where capacity is missing.
How the changeover is planned
The warehouse usually has to keep working during a retrofit, so the migration strategy is the core of the project. Common approaches are:
- Phased migration: the system is converted section by section or aisle by aisle, and each section is tested before the next one starts.
- Weekend and holiday changeovers: each step fits into a planned shutdown window.
- Parallel preparation: new cabinets and software are built and tested beforehand, so that work on site is limited to the changeover itself.
- Fallback plan: for each step it is defined how the previous state can be restored if a test fails.
Testing the new software against a simulation of the system before the changeover (virtual commissioning) shortens the time needed on site and reduces the risk at restart.
How a retrofit project runs
- On-site assessment: mechanics, electrics, controls and software are examined and documented.
- Concept: scope, migration steps, shutdown windows and risks are defined.
- Design and preparation: electrical design, software and cabinets are completed and tested.
- Changeover: the steps are carried out in the planned windows.
- Commissioning and handover: the system is tested with real products, and operators and maintenance staff are trained.
- Service: maintenance and support continue after the handover.
Frequently asked questions
Can a system from another manufacturer be retrofitted?
Yes. The system is examined in an on-site assessment, and the control concept is rebuilt on a current platform. Complete original documentation helps but is not a precondition.
Does the warehouse have to stop during a retrofit?
Not completely. The changeover is planned in phases and in shutdown windows such as weekends, so the operation continues between the steps.
How long does a retrofit take?
It depends on the size of the system and the shutdown windows available. Design and preparation take most of the time; the work on site is concentrated in the changeover windows.
Does a retrofit increase capacity?
New controls and drives can raise availability and, in some cases, throughput. If the operation needs considerably more capacity, the retrofit is combined with new equipment.
Retrofit projects at PBC Technology
PBC Technology modernizes existing sorter, conveyor and AS/RS installations: PLC, drives, HMI, SCADA and software are renewed in phases while the working mechanical equipment is kept.