As the mining sector grapples with a turbulent commodity cycle, rising costs, constrained capital, and the increasing operational complexity of delivering production now while ensuring access to future reserves, capital optimisation has become a strategic necessity. Increasingly, mining firms are looking to adopt phased approaches by designing minimally viable mines to start generating revenue and then scaling up in phases through self-funding.
Enter ROCx– rigorous optimisation of capital expenditure: a structured, facilitated approach for optimising the technical study design to deliver the best possible financial results without compromising the engineering outcome.
Reini Cronje, an associate principal at Partners in Performance, Part of Accenture, shares how ROCx is helping mining companies unlock billions in value. Successful implementation has already led to NPV improvements between 40%–80%, and these results are common.
Why ROCx matters in mining
ROCx is more than a cost-cutting exercise. It’s a structured, value-focused approach to capital project optimisation that interrogates every assumption (and their trade-offs) underpinning a project’s design.
What sets ROCx apart is its focus on business outcomes. It systematically interrogates the main drivers of NPV and IRR –scale, capex, opex, and time to first cash flow–before challenging the fundamental design assumptions that underpin them. Rather than accepting capex, opex, or construction timelines as fixed, ROCx explores whether these are truly immovable or if better trade-offs can be made.
“We’re not trying to be better engineers than the project team,” Cronje explains. “We help them see the link between the project’s economic value and the assumptions they’re making. It’s not an indictment of the project team, it’s just that they are often so deep in the details that they lose sight of the value drivers. ROCx helps them step back and ask: are we solving the right problem in the right way?”
At its core, ROCx is a facilitated process where Partners in Performance, Part of Accenture, works alongside the client design, engineering, procurement and construction teams to arrive at an optimised design that is still owned by the team. It’s not a technical audit or review, it’s a short, sharp intervention. Typically a few weeks long, it can be applied at any stage of project development, from concept through to the feasibility study.
In a recent ROCx engagement focused on a mining-led development schedule, Cronje’s team tackled a project with a 10-year gap between investment and steady-state production. “That’s a long time to wait for value,” he notes. “And in the meantime, the mine is investing capital and paying salaries and overheads without generating revenue.”
The power of continuous improvement thinking from the start
Unlike capital projects where infrastructure or shaft sinking dominates the critical path, the project recently supported by Partners in Performance, Part of Accenture, was driven by mining development. That requires an additional lens focused on accelerating decline development and optimising mine planning and design in addition to the normal levers (e.g., capex, opex, scale, infrastructure schedule).
While CI is often associated with operational phases, ROCx demonstrates the power of CI in the design phase. “We’re applying CI thinking to mine design,” Cronje explains. “That means challenging assumptions about shift patterns, equipment availability, and even the size of the declines.” Development rates can be significantly improved by making fundamental, practical changes. These can include rethinking shift patterns, introducing twin-boom jumbos, or enabling multiple blasts per day through early ventilation upgrades.  Challenging design assumptions, a staple of the ROCx methodology, makes them more realistic (e.g. accurate equipment availability), thereby avoiding over-promising and under-delivering.
Unlocking hidden value in projects
As South Africa’s mining sector looks to extend the life of existing assets and navigate capital constraints, ROCx offers a proven path to doing more with less and unlocking billions in value through smarter, faster, and more collaborative project design.
What makes ROCx especially powerful is its ability to bridge the gap between technically sound engineering and economically optimal outcomes. It’s a business-first approach that challenges conventional design thinking. By interrogating assumptions and aligning technical decisions with financial outcomes, ROCx helps teams uncover hidden value and make better trade-offs.
This approach is particularly impactful at the end of the pre-feasibility stage, when designs are mature enough to optimise but are not yet locked in. And while it can be uncomfortable to revisit long-held assumptions, the payoff is clear: NPV improvements of 40%–80% are achievable.
“Ultimately,” says Cronje, “it’s about helping teams build better projects that are realistic, value-driven, and ready to deliver from day one.”