The Real Cost of Down Time: Why Your Epiroc Spare Parts Strategy is Probably Costing You More Than You Think

You Think You Know What A Stalled Drill Rig Costs

If you've ever had a $500,000 drill rig sitting idle because of a failed hydraulic seal, you know that feeling. The clock is ticking on your production target, the hourly rate for the crew is still running, and you're on the phone trying to find a part that should have been in your inventory.

Let me give you a concrete number from my own tracking: I once calculated that a single day of unplanned downtime on a key underground rig cost us approximately $18,000 in lost production and crew time—not including the expedited shipping for the replacement part.

Here's what I've learned after analyzing $800,000 in cumulative spending across 6 years of managing Epiroc parts inventory at a mid-sized mining operation: most people think the problem is the price of the part. The real problem is the cost of not having it.

The Surface Problem: 'These Parts Are Expensive'

Sure, when I first took over procurement, looking at a $1,200 price tag for a genuine Epiroc hydraulic hammer seal kit felt painful. I remember thinking, 'There's no way this is worth that much. I can get an aftermarket kit for $350.' My gut said I was overpaying for a brand name.

The numbers said one thing. My gut said another. Every spreadsheet analysis pointed to the aftermarket option being 65% cheaper upfront. It seemed like a no-brainer. But something felt off, and it was the kind of 'off' you only develop after you've gotten burned on hidden costs before.

The Deeper Layer: What You Don't See on the Invoice

Let me explain why my gut was right, and why 'cheaper' is a trap. Looking back, I should have seen it coming. At the time, I was focused on the unit price.

People think lower-cost parts save money. Actually, lower-cost parts that fail more often increase total cost dramatically. The causation runs the other way: reliable parts justify their price because they reduce the risk of the bigger expense—downtime.

I want to say we saved 40% in the first quarter by switching to aftermarket seals, but don't quote me on that exact figure—I'd have to dig up the old spreadsheet. But what I do remember clearly is the cost of the failures that followed.

In Q3 2024, when we switched vendors for a batch of hydraulic filters for our EPIROC drill rigs, we saw a 15% failure rate within the first month. That 'savings' on parts was wiped out by a single 8-hour unscheduled maintenance event. The total cost? We lost a day of production plus a $400 emergency part we had to airfreight in.

The assumption is that rush orders cost more because they're expedited. The reality is they cost more because they're unpredictable and disrupt planned workflows. It's the unplanned nature of the failure that really kills you.

The Real Cost: How Bad Can It Get?

Estimates from industry groups suggest that unplanned downtime in mining can cost anywhere from $5,000 to over $50,000 per hour depending on the operation. While those figures are based on larger operations, the principle holds true for any business running heavy equipment.

In my experience tracking over 6 years of invoices and downtime logs, I found that 80% of our 'budget overruns' for maintenance came from emergency repairs and expedited logistics—not from the cost of scheduled maintenance or parts. We had a policy of buying the cheapest parts that 'looked right,' and it was costing us a fortune. We implemented a policy of verifying part numbers with our Epiroc dealer first. It cut our emergency procurement costs by about 30% in the first year.

Bottom line: the lowest quoted price for an Epiroc spare part is almost never the lowest total cost. A $50 saving on a valve that fails after 500 hours instead of the genuine part's 2,000-hour lifespan is a bad deal. Especially when that failure happens during peak production.

The (Brief) Fix: Build Your Spare Parts Strategy Around Reliability, Not Price

So what do you do? The fix isn't complicated, but it requires a shift in thinking.

1. Stop thinking about parts cost. Start thinking about risk cost. Every part you buy carries a risk of failure. Genuine Epiroc parts carry a known, low risk. Aftermarket parts carry an unknown risk. Assign a value to that risk.
2. Audit your downtime. Take your last quarter's worth of unplanned maintenance events. Calculate the lost production hours and the cost of emergency parts and shipping. I bet that number is larger than your annual spare parts budget.
3. Build a 'critical spares' inventory. For every piece of key equipment, identify the 5 parts that cause the most downtime. Keep one of each in stock. Paying for inventory is much cheaper than paying for a shutdown.

An informed customer asks better questions and makes faster decisions. I'd rather spend 10 minutes explaining the difference between a genuine Epiroc seal kit and an aftermarket one than deal with a mismatched expectation later or, worse, a machine that's down because of a cheap part.

If you could redo a single procurement decision from last year, what would it be? For me, it would be acting on that gut feeling about the cheaper parts sooner. But given what I knew then—nothing about the aftermarket vendor's failure rate history—my choice was reasonable. Now I know better. And I track everything.