How to Build a Critical Spares List for a Bottling Line (Sidel, Krones, Zalkin)

Every bottling line has a few parts that can stop everything. The problem is that most storerooms are full of the wrong ones — parts that failed once, years ago — while the truly critical items are missing. A critical spares list fixes that.

This guide walks through a simple method, using a typical line with a Sidel blow moulder, a Krones filler and labeller, a Zalkin capper and a Robopac stretch wrapper.

Step 1: Map the line

List every machine in order, from preform infeed to pallet:

1. Blow moulder.
2. Filler and capper.
3. Labeller.
4. Case packer.
5. Palletiser and stretch wrapper.

Add utilities that the whole line depends on — compressed air, cooling and CIP.

Step 2: Score each component

For each major component, score three factors from 1 to 5:

• Impact — does failure stop the line, slow it, or affect quality?
• Likelihood — how often does it fail, based on history and wear?
• Lead time — how long does a replacement take to arrive?

Multiply the scores. The highest totals are your critical spares.

Lead time is the factor most plants forget. A part that fails rarely but takes eight weeks to arrive can be more critical than one that fails monthly but is available tomorrow.

Step 3: Typical critical parts by machine

Blow moulder (Sidel): heating lamps, preform transfer arms, spindle shafts, mould locking components. On KOSME machines, add mould locking pins and preform starwheels.

Filler (Krones): filling valves, vacuum seals, centering bells, starwheels.

Capper (Zalkin): capping chucks, magnetic clutches, torque limiters, cap feed tracks.

Labeller: glue rollers, label cutting blades, vacuum drums. See the labelling systems category.

Stretch wrapper (Robopac): friction clutch discs, stretch rollers, inverter modules, limit switches.

Step 4: Decide stock levels

• Critical, long lead time: keep at least one on site.
• Critical, short lead time: keep a minimal quantity or arrange guaranteed express supply.
• Non-critical: order on demand.
• Consumables: stock based on usage, with a reorder point.

Step 5: Store and label properly

• Store parts per machine, clearly labelled with part number and machine position.
• Protect elastomers from heat, light and ozone.
• Record shelf life for seals and rubber parts.
• Keep the parts list and photos in your maintenance system.

Step 6: Review and improve

Review the list at least once a year:

1. Which parts failed, and were they on the list?
2. How long did replacements take?
3. Which parts were never used and can be reduced?
4. Have any parts become discontinued?

Each review makes the list more accurate and frees cash tied up in the wrong stock.

Budgeting the first stock

Building the first critical spares stock can be a significant investment. Financial solutions can spread the cost, and our spare parts team can review your list across all brands in one go.

For more context, read our guides to Krones change parts and combating machine downtime.

Key terms explained

Criticality: how much a part's failure affects safety, quality or production.

MTBF (mean time between failures): the average running time between failures of a component.

Reorder point: the stock level at which a new order is placed so the part never runs out.

Bill of materials (BOM): the structured list of components that make up a machine.

Using your maintenance system

A critical spares list works best inside your CMMS or ERP rather than in a separate spreadsheet:

• Link each spare to the machine and position where it is used.
• Store part numbers, photos, drawings and approved suppliers.
• Set reorder points so purchasing is triggered automatically.
• Record every issue from stock against a work order.

After a few months, the system shows real consumption and failure data, which makes the next review much faster.

Don't forget utilities

Bottling lines depend on compressed air, cooling water, steam and CIP. A failed compressor, cooling pump or CIP valve can stop the whole line just as quickly as a filler fault. Include the critical spares for these utilities in the same list, with the same scoring method, so they are not forgotten in a separate department.

A worked example from a water bottler

A mineral water bottler had a storeroom full of parts but still suffered long stops. A review showed that many stored parts were for machines no longer in use, while critical items for the blow moulder and capper were missing.

The team scored every component on impact, likelihood and lead time. Around forty items made the critical list. Obsolete stock was sold or written off, freeing cash, and the critical items were ordered and stored per machine.

In the following year, average downtime per breakdown fell significantly because the right part was usually already on the shelf.

Common mistakes to avoid

• Stocking what failed last instead of what is most critical.
• Ignoring lead time when ranking parts.
• Keeping obsolete parts for machines that have been removed.
• Poor labelling, so parts cannot be found in an emergency.
• Never reviewing the list after breakdowns or line changes.

Key takeaways

• Map the whole line, including utilities, before ranking parts.
• Score each component by impact, likelihood and lead time.
• Keep long-lead critical parts on site; arrange express supply for the rest.
• Store, label and document parts per machine.
• Review the list at least yearly and after every major breakdown.