Our industry is built on experience. Each edition, we feature someone who knows their field inside and out, sharing the knowledge they’ve gained over many years. From practical advice to lessons learned the hard way, this is insight you won’t find in a manual. This month we hear from Isuru Dissanayake, Group Inventory Manager across NSW and QLD for Whitehaven.
In coal mining, the biggest machines usually attract the most attention. Draglines, excavators, CHPPs and haul trucks dominate site tours, boardroom discussions and capital plans. But often, the difference between steady production and costly downtime comes down to something far smaller – and far quieter – tucked away on a warehouse shelf.
A $25 sensor.
A hydraulic hose.
A $12 seal kit.
When one of those parts isn’t available at the right moment, a multi-million-dollar machine can sit idle. Production slows, labour waits, contractors stand by and revenue stops.
That’s why inventory planning in mining isn’t about stock levels – it’s about operational uptime.
Coal mining is a continuous, high-pressure environment where every hour of downtime matters. In many operations, lost production can exceed $10,000 an hour, and the knock-on effects ripple quickly across the site. Strategic supply chain planning reduces that risk by aligning inventory decisions with real operational demand – planned shutdowns, live work orders and known failure points – rather than reacting after something breaks.
When inventory is planned properly, long-lead items are ordered early, critical spares are available when needed, and emergency freight becomes the exception rather than the rule. In that sense, inventory control acts as operational insurance. Without planning, we rely on luck. With planning, we rely on data.
Modern systems like SAP’s Material Requirements Planning are often viewed as back-office tools, but when master data is accurate, they function more like decision engines. They can automatically generate purchase requisitions, trigger orders based on minimum and maximum stock levels, and predict future demand using usage history and shutdown schedules. The real value, however, comes from exception management – the early warning signs that highlight where a mine is about to lose time or money.
Those exceptions can take many forms. A cancelled or delayed work order may signal the need to defer or cancel a purchase before excess stock arrives. An urgent breakdown can justify advancing a purchase order or upgrading freight to avoid extended downtime. Duplicate purchasing can be stopped before unnecessary spending occurs. Each exception represents a moment where intervention can protect uptime or preserve capital.
One real example involved a critical hydraulic cylinder for a digger that was already in transit under standard freight conditions, with an expected delivery time of ten days. When the digger unexpectedly broke down, exception management allowed the issue to be identified immediately. The supplier was contacted, freight was upgraded to air, and the part arrived within 48 hours. A single inventory decision prevented extended downtime and avoided a significant production loss.
In another case, a gearbox valued at $180,000 had been ordered for a planned shutdown scheduled for April 2025. When that shutdown was pushed out to 2026 and the associated work order cancelled, exception management flagged the change. Without intervention, the purchase order would have converted to stock, tying up capital for more than a year. Instead, the delivery was deferred and the purchase order cancelled. The result was $180,000 in working capital preserved, no impact on operations, and no risk of storage damage or obsolescence.
Despite increasing automation, the role of the Inventory Controller remains critical.
Automatically generated purchase requisitions still require human review to prevent costly mistakes. Quantities must reflect actual installation requirements rather than planned figures, stock already in transit must be considered, freight modes need to be appropriate, and work order consumption must be verified. The goal is not to order less – it is to order correctly.
All of this relies on one foundational element: master data accuracy. Incorrect lead times can trigger unnecessary express freight. Incorrect units of measure can result in over- or under-ordering. Missing minimum and maximum levels can lead to unexpected stockouts on fast-moving items. Automation only delivers value when the data behind it can be trusted.
Reporting and analytics then turn that accurate data into action. Visibility over slow-moving or obsolete stock enables returns, transfers or write-downs before value is lost. Reviewing past-due work orders with reserved materials highlights parts sitting unused in limbo. Open purchase order dashboards and delivery-in-full, on-time reporting hold suppliers accountable. Exception dashboards show where action is needed today – not after a problem has already occurred.
Instead of debating opinions such as “we might have too much stock,” the data tells a clearer story: how much capital is tied up, where it is, and which items can be addressed immediately. Accountability improves when decisions are evidence-based.
The key lesson is that inventory is not static. It is a living system that requires daily attention.
Trusting the system blindly creates risk, but combining automation with experienced oversight protects uptime. More stock does not necessarily mean more safety. Strategic stock does.
In the end, inventory control may not be the loudest part of coal mining, but it is one of the most critical. Quiet decisions made in the warehouse and the system every day are often what determines whether production continues smoothly – or grinds to a halt.
| Want to dig deeper? Connect with Isuru Dissanayake on LinkedIn. |
| IN THE KNOW: FAST FACTS • Small parts cause big downtime – critical spares matter as much as big assets • Inventory planning protects uptime, not just stock levels • Accurate master data is essential for automation to work • Exception management highlights risks before they become breakdowns • Emergency freight is a last resort – planning should come first • Inventory Controllers are a critical line of defense against downtime • More stock doesn’t equal more safety – strategic stock does |
