For procurement and operations leaders in food and beverage manufacturing, few line items are harder to justify in a capital budget than a control system upgrade. There is no new conveyor to point to, no shiny new filler, just a cabinet of relays, terminals, and a processor that has been quietly running the line for fifteen years. Yet ageing programmable logic controllers, or PLCs, are consistently one of the leading causes of unplanned downtime on Australian beverage and FMCG lines, and the cost of deferring an upgrade is almost always higher than the cost of the upgrade itself.
The real cost of an ageing control system
When a PLC fails on a production line, the cost is rarely limited to the repair invoice. A stopped filler or labeller on a beverage line can halt an entire production run, idle packaging staff, delay despatch, and in the worst cases put product quality at risk if temperature or pressure control is lost mid process. Add in the premium cost of emergency electrical callouts, the scarcity of technicians who still understand obsolete processor families, and the difficulty of sourcing spare parts for discontinued hardware, and the true cost of an unplanned breakdown climbs well beyond the headline repair figure.
Older systems also tend to fail without warning. Where a modern PLC and HMI combination can flag drifting performance, intermittent faults, or component wear before a full failure occurs, legacy systems built on superseded processor families generally cannot. Operations teams are left reacting to breakdowns rather than planning around them, which is precisely the opposite of what a procurement function wants from its capital asset base.
Signs a control system is due for renewal
There are a handful of reliable indicators that a PLC upgrade should move up the priority list. Recurring, unexplained faults that electricians cannot fully diagnose are usually the first sign. So too is a growing reliance on a single technician or contractor who happens to understand the legacy programming, which creates a serious single point of failure for the business. If the manufacturer has discontinued support or spare parts for the processor family, every additional month of operation is a gamble. Finally, if the current system cannot talk to newer line equipment, vision systems, or data collection platforms, it is actively holding back the plant’s broader automation and reporting goals.
What a structured PLC upgrade involves
A properly scoped upgrade is not simply a hardware swap. It begins with an audit of the existing control philosophy, wiring, and I/O, followed by a design phase that maps out the new platform, typically built around Allen Bradley or Siemens processors depending on the existing plant standard and the skills available on site. From there, the programming is rebuilt or migrated, the HMI is redesigned for clarity, and the system is commissioned with minimal disruption to the production schedule, often during a planned shutdown window.
One useful example is a recent project where an automated control system was implemented to manage two glycol refrigeration units responsible for cooling large beer tanks. The system, built on a Siemens 1500 series PLC with a Siemens touchscreen HMI and ABB variable speed drives, uses temperature and pressure feedback with PID control loops to regulate cooling precisely. Because beer temperature falling out of specification is a critical quality issue, the reliability of that control loop directly protects product quality, not just uptime. This is the kind of outcome a well-executed PLC upgrade should deliver, control that is both more stable and more transparent than what it replaced.
Building the ROI case
For an operations or procurement stakeholder, the business case for a PLC upgrade should be built around three numbers, the cost of historical unplanned downtime attributable to control faults, the premium paid for emergency electrical support versus planned maintenance rates, and the risk exposure created by relying on obsolete or single sourced expertise. When these are laid out against the cost of a structured upgrade, the payback period is frequently inside twelve to eighteen months, particularly on lines where downtime directly delays despatch or triggers contractual penalties with retail or wholesale customers.
It is also worth factoring in the indirect benefits. A modern HMI gives operators clearer fault diagnostics, which reduces the time technicians spend troubleshooting and shortens mean time to repair when issues do occur. Better data visibility also supports broader continuous improvement initiatives, since production data becomes available for analysis rather than disappearing into a legacy black box.
Choosing the right partner
Because a PLC upgrade touches safety systems, production continuity, and product quality simultaneously, the choice of engineering partner matters as much as the choice of hardware platform. Bevtech Engineering and Automation has worked across the food and beverage manufacturing sector for over 25 years, with a team of control system engineers, industrial electricians, and TUV functional safety engineers experienced in both Allen Bradley and Siemens platforms. That dual platform capability is particularly useful for sites that have grown through acquisition or expansion and ended up with a mixed fleet of control systems, since it avoids locking the business into a single vendor relationship for future support.
Bevtech also offers 24/7 electrical shift coverage, which matters during the commissioning phase of an upgrade, when a new system needs close monitoring through its first full production cycles. For plant and operations managers planning a control system renewal, that combination of multi platform expertise and ongoing maintenance support reduces the risk profile of the project considerably.
Next steps
If your facility is relying on a control system that nobody fully understands, or your maintenance team is spending more time firefighting electrical faults than running planned preventative work, it is worth having a conversation before the next failure forces the decision. Bevtech Engineering and Automation, based at 25 Silvio St, Richlands QLD, can assess your existing control architecture and outline a staged upgrade path that fits your production calendar and budget cycle. Contact the team on +61 400 881 321 or admin@bevtech.com.au to arrange a site assessment.
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