- Advanced Process Control
- Operational Technology
- Mineral Processing
- Expert Interview
Drew Clements on what mineral processing sites need to know before they invest
Drew Clements is Mipac’s Optimisation Team Lead – a metallurgist and former control room operator who has spent his career moving across sites, commodities, and control problems. We sat down with Drew to get his unfiltered view on Advanced Process Control readiness: why so many APC projects underperform, what a rigorous site audit looks like from the inside, and the one question he wishes every site would ask before signing anything.
Advanced Process Control (APC) can deliver meaningful improvements in throughput, stability, and operational efficiency at mineral processing facilities. Most people in the industry know this. What far fewer understand is what needs to be in place before APC will actually work, and how often those foundations are missing when a site decides to invest.
Drew Clements has seen this gap play out repeatedly. As Mipac’s Optimisation Team Lead, he has worked across dozens of sites, audited control systems in multiple countries, and been called in to diagnose APC deployments that have quietly been switched off. His view on why this happens is direct and consistent: the software is rarely the problem.
Everyone focuses on the destination
When a site comes to Mipac saying they want to implement APC, the conversation almost always starts in the same place.
“Everyone tends to focus on the end objective and not the steps that are going to get them to that end objective. We get a lot of people coming to us going, I want to put an APC in. I want a remote operation centre. And it’s like - okay, what’s your technology maturity level on the site like?”
The initial enthusiasm is real. So is the gap. As Mipac starts asking questions about site readiness, clients begin to realise there is significantly more groundwork involved than they anticipated. The exception, Drew notes, is sites that have been through an APC project before. Those clients do not arrive asking for the end result. They ask for the first step, because they already know what the process involves.
Part of the confusion is structural. Over the years, vendors have described a wide range of products as APC, including systems that are, in Drew’s assessment, little more than Advanced Regulatory Control (ARC): something achievable within an existing control system without an additional purchase.
“No one comes to us with a clear understanding of what an APC actually is.”
APC selection is further complicated by the fact that not all APCs suit all applications. Drew describes a spectrum running from tier 1 to 3 systems – single-method tools using fuzzy logic, gain scheduling, or a specific algorithm – through to tier 4 and 5 toolbox APCs, which carry up to a many different methods and apply the right one to the problem at hand. Matching the right tool to the right application matters as much as choosing APC over conventional control. As Drew puts it: if you have a screwdriver and you need a hammer, the brand of screwdriver is not the issue.
Why APC projects actually fail
When APC deployments underperform – and Drew sees this regularly – four failure modes account for almost every case.
Expertise walks out the door
Once the installer leaves, the model predictive controller gradually drifts as ore bodies and process conditions change. Without someone on site who understands how to retune it, the APC gets switched off. Drew echoes conversations he has had on multiple sites:
“Why is it off? Oh, it’s drifted away from its original model and we’re in a different domain now.”
The APC may be functioning exactly as designed. The problem is that nobody who remains on site knows how to keep it current. This is why Drew’s standard engagement roadmap now couples the optimisation pathway with an explicit training pathway: documentation, e-learning, and materials written in the language of the local operators, so that when the project champion eventually moves on, the knowledge stays with the facility.
Instrumentation that was never fixed or has since deteriorated
The underlying instruments were either not resolved before implementation or were fixed and have since degraded. Bad data produces bad control decisions. Operators lose confidence, and the system stops running. This failure mode is directly connected to one thing: skipping the foundational readiness steps before committing to APC.
The black box problem
When operators cannot see why an APC is making the decisions it makes, trust erodes quickly. Drew has seen APC systems physically installed in separate rooms from the control room, invisible to the people nominally responsible for the process.
“The APC may have been making the right decisions. But how would the operators know?”
Without visibility, operators switch the system off and manage the process themselves. If they get a result, the APC never comes back on. Mipac has been brought in specifically to integrate black box APC systems into SCADA environments, making the decision logic visible to the control room, which consistently improves operator engagement and the proportion of time the APC is actually running.
People change
Drew is unambiguous about this being the most significant factor of all.
“If you don’t manage the people change and deliver a program that targets your early champions and builds that fear of missing out for others, the pushback is greater than that one person can deal with. They get frustrated or they give up.”
The antidote is momentum. Drew describes a recent digital software rollout where three of four operating crews got on board and effectively told the fourth there was no rolling back. That is the snowball effect in practice: one champion influencing a crew, one crew influencing another
What the audit actually looks like on site
Mipac’s APC Readiness Audit moves through three phases: remote preparation, on-site engagement, and post-visit recommendations.
Before arriving, the team reviews P&IDs, historian data, and control system documentation, building a picture of what the critical instrumentation is, where the gaps are likely to be, and which questions need to go to which people.
“Nothing beats two feet and a heartbeat.”
On site, that means walking the process area, looking at what the data cannot show, and talking to the people who actually run the facility – not just reviewing systems from a desk. Those conversations consistently surface problems invisible to any digital system.
On one site, Drew found that instruments on an acid leach circuit were not being calibrated: not from negligence, but because acid was falling from the top of the tanks into the area where the instruments were located. The field technician would not walk in, and for good reason. That safety reality appeared in no historian, no P&ID, no control loop report.
On another site, instrument replacement times were running at nearly three days. The reason became clear on visiting the maintenance coordinator: a literal stack of paperwork orders waiting to be manually entered into the ERP system. A shift to mobile data capture eliminated the backlog. Replacement time dropped to one hour.
And sometimes the issue is simpler still.
“We had a regulatory valve operating in ways that we couldn’t understand from the data. We got out in the field and there was a piece of rope tied around it, holding it in position. The control valve was trying to work. The rope was stopping it. The rope doesn’t show up in anyone’s diagrams or historian data.”
The audit closes with a prioritised roadmap: which areas to address first based on return on investment, what Mipac can deliver, what the site needs to handle internally, and a vendor recommendation drawn from Mipac’s own comparative testing of more than a dozen APC providers across the same benchmark scenario. Because Mipac is vendor-agnostic, that recommendation is based on fit for purpose, not commercial relationship.
The budget reality most sites miss
One of the most underappreciated aspects of APC planning is the total cost of getting there. Sites typically see the APC software cost alongside an ROI figure (often quoted at three to six months) and treat that as the full investment picture.
“What they’re not seeing is the instrumentation improvements, the SCADA-level work, the people change, the training programs. All of that takes additional time and comes with additional cost.”
On a regular facility seeking incremental improvement, Drew’s experience is that genuine ROI is closer to twelve months when all the underlying work is properly accounted for. That is not a reason to walk away from APC. It is a reason to plan with clear eyes.
Drew’s honest advice - and the question nobody asks
For a plant or processing manager who has been thinking about APC for a while but has not yet committed, Drew’s advice is immediate.
“Audit the system that’s already there. An independent third-party audit outside of your own organisation will give you clarity. It will recognise the blind spots you can’t see in your own plant.”
The audit does not always result in a large program of works. Drew recalls one site that scored four out of five on the readiness assessment and decided to do nothing further. They had achieved their objective of maximising what their existing system could deliver. The audit gave them confidence and a clear picture. That, in itself, was the value.
And the question Drew wishes every site would ask before selecting an APC vendor?
“Is this the right APC for what I need it to do?”
Most sites arrive with a vendor already in mind; chosen for their sales presence, their brochure, or the appearance of their interface. The question of fit is almost never raised. There are more than twenty APC products on the market, and they are not equivalent.
“There’s everything from old Datsuns to Lamborghinis out there. But if you just need to drive down the road to go to the shop, you might be right with the Mazda.”
Key takeaways
APC success depends on what is in place before implementation (instrumentation reliability, control loop health, data quality, and operational discipline) not the software alone.
The four most common failure modes are expertise loss after handover, instrumentation deterioration, operator distrust of black box systems, and inadequate change management.
On-site engagement during a readiness audit consistently surfaces problems that are invisible to any data system.
Full ROI on APC typically takes longer than vendor quotes suggest, once all underlying foundational work is included.
The most important question to ask before selecting a vendor is whether that specific APC is the right fit for your application, ore type, and operational capability.
Want to really understand if your plant is ready for APC?
Mipac’s APC Readiness Audit is a structured six-stage engagement – from problem definition through to business case development – designed to give mineral processing sites an honest picture of where they stand before committing to an APC investment.
Or contact our team to arrange a discovery calls →
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