Direct answer
A critical spares list should contain parts whose failure would stop production, compromise safety or quality, and which cannot be obtained or substituted within the acceptable recovery time. Prioritise by consequence and procurement lead time rather than stocking every component.
Key takeaways
- Define the maximum acceptable recovery time for each machine.
- Use failure history, condition and supplier lead times.
- Stock, preserve and identify the right quantity.
- Review after use, modification and supplier change.
Set a measurable objective
Criticality depends on business context. A part may be non-critical where parallel capacity exists but essential on a single line supplying a time-sensitive customer.
- Map single points of failure
- Record backup equipment and manual alternatives
- Set recovery-time objectives
- Identify safety- and quality-critical components
Measure the current production condition
Combine maintenance records with the supplier bill of materials. Check whether controls, drives, sensors and proprietary assemblies are still available and whether a stocked spare needs software or configuration.
- Record component failure frequency
- Confirm normal and emergency lead time
- Check shelf life and storage conditions
- Identify programming, calibration or setup required
Plan the work in a controlled sequence
Define minimum and maximum stock, storage location, preservation, issue control and reorder point. Store software, parameter files and drawings with the physical recovery plan.
- Label parts with machine and drawing references
- Protect seals, electronics and lubricated parts
- Rotate shelf-life-controlled items
- Maintain PLC, HMI, drive and recipe backups
Hold the improvement after handover
A spare consumed in a breakdown should trigger replenishment and root-cause review. Update the list when machines are modified or components become obsolete.
- Audit stock against the register
- Test high-risk electronic spares where appropriate
- Track obsolete and last-buy notices
- Record compatible alternatives and approval
Comparison table
| Stage | Customer decision | Evidence |
|---|---|---|
| Objective | Define the maximum acceptable recovery time for each machine. | A numerical target and owner |
| Baseline | Use failure history, condition and supplier lead times. | Representative production records |
| Action | Stock, preserve and identify the right quantity. | A timed plan with responsibilities |
| Control | Review after use, modification and supplier change. | Approved standard work and review data |
Free working templates
Download these files and adapt them to the actual machine, product, site and acceptance plan.
Related buyer guides and tools
Relevant machinery and support routes
Use the guide to define the requirement, then compare the specialist routes below against representative product, packaging and output evidence.