Direct answer
Commission a mechanical condition survey. If remaining mechanical life exceeds the payback horizon and the capacity ceiling is acceptable, retrofit. Otherwise replace.
When this decision arises
- Obsolete controls with scarce spares
- Machine cannot produce required data
- Safety compliance no longer demonstrable
- Capacity ceiling below future requirement
- Long replacement lead times
The options on the table
Control and drive retrofit
Typical cost a fraction of replacement; retains proven process behaviour.
Partial replacement
Replace the worn module, retrofit the rest.
Full replacement
Where capacity, hygiene or mechanical condition are the binding constraint.
Defer with spares cover
Bridge with critical spares while a larger programme is planned.
Decision matrix
| Criterion | Favours retrofit | Favours replacement |
|---|---|---|
| Mechanical condition | Sound, wear localised | Structural wear or fatigue |
| Capacity | Sufficient for the plan | Below future requirement |
| Hygiene / compliance design | Adequate | Non-compliant by design |
| Downtime tolerance | Short window available | Extended change possible |
| Capital availability | Constrained | Available |
Decision criteria
What to prepare before engaging engineering companies
- Mechanical condition survey with remaining-life estimate
- Maintenance and downtime cost history
- Capacity requirement over the planning horizon
- Available shutdown window
What to measure
Frequently asked questions
Is a retrofit always cheaper?
In capital terms, usually. Over the full horizon it depends on remaining mechanical life — a retrofit onto a worn base transfers the problem forward.
Related engineering knowledge
Independent, buyer-side and supplier-neutral
Global B2B Group does not sell machines and does not represent equipment manufacturers. This material is published to help industrial organisations define the problem, prepare the specification and structure the investment before engineering partners are selected.