Glossary · Automation fundamentals, platforms and components
Retrofit
Also known as: Modernization
German: Retrofit
In industrial automation, a retrofit is the modernization of an existing machine or plant by replacing or adding components, such as controllers, drives, HMIs, sensors or networks, to extend its service life, add functions or replace obsolete parts, while keeping the mechanical base.
- Automation components
In one sentence
A retrofit modernizes an existing machine or plant, for example new controls, drives or sensors, to extend its life or add functions.
Example
A 20-year-old press receives a new PLC, safety controller and HMI because spare parts for the original controller are no longer available.
Explained in context
Context cards connect this term with others to answer one question. Also in British English and German.
How it applies
- Engineering: Start with an inventory of the existing machine: circuit diagrams, programs and actual wiring often differ. Plan interfaces to parts that stay unchanged.
- Compliance: A retrofit can change the machine's risk. Assess whether it is a Substantial modification under the Machinery Regulation (EU) 2023/1230; if so, the modifier takes on manufacturer obligations for the modified machine. The legal test is explained in Retrofit under the Machinery Regulation. Handle the change through Management of change (MOC).
- Documentation: Update the technical documentation, circuit diagrams, safety functions and operating manual to the new state. Mark which parts of the old documentation are obsolete, and keep the previous Configuration baseline for reference. The operator's documents need the same update: the risk assessment and, in plants with explosive atmospheres, the explosion protection document — the old plant may keep its design, but its documents enjoy no grandfathering.
Retrofit vs. repair
A repair restores the original state with equivalent parts. A retrofit changes the design, which is why it needs a new risk assessment and updated documentation.