Connecting Life of Mine Planning and Finance in OneStream

Uncovering Real Value with Life of Mine Planning

Mining companies plan on a different scale than most organizations. A mine's budget covers twelve months. Its Life of Mine plan can cover decades.

Most mining companies keep the two in separate systems, often Excel workbooks that analysts update manually with data pulled from mine-planning software and other external sources.  Even when one team owns both, it builds the life-of-mine plan and the budget separately, duplicating the work and updating each on its own cycle. The gap between them shows up where finance can least afford it: capital approvals, impairment testing, closure provisioning, and long-term investment decisions.

In our recent webinar, we showed how OneStream connects long-range mine planning and financial planning within a single planning environment. 

The Problem Isn't the Plan

A Life of Mine (LOM) plan models how a mine will perform from today through closure. It combines production assumptions, operational drivers, costs, and capital requirements into a long-term view of an asset's economics. It also sets the timeline that much of the finance work depends on, including when capital is spent, when production tapers, and when closure costs arrive.

Most mining organizations already have a LOM plan. The challenge is keeping it aligned with the budgets and forecasts that run the business. When LOM assumptions change in only one system, such as Excel, and the budget operates in another, finance teams reconcile the differences by hand. Over time, the long-range plan and the financial models built on it drift apart.

The disconnect shows most clearly when a major production assumption changes. A revised mine plan has to reach every model that depends on it, and those models often live in different places with different owners.

One Model, Changing Granularity

OneStream handles long-range planning through scenario design, which lets planning granularity change as the horizon extends.

A plan might run monthly for the near term, quarterly through the medium term, and annually for longer-range projections. Detail stays where decisions need it. The near-term months support operational budgeting and cash management, while the outer years support investment cases and asset valuation.

The model stays manageable because it doesn't carry monthly detail thirty years out. Finance works within one planning framework that adapts over time, instead of maintaining separate short-term and long-term models and reconciling the seam between them.

Different Costs Behave Differently

Not every cost follows the same pattern over the life of a mine. Some costs move with operational activity, driven directly by physicals such as tonnes mined, tonnes processed, or equipment hours. Others move primarily with inflation, contract escalations, market conditions, or broader economic factors, regardless of how much the mine produces.

The framework discussed in the webinar treats each cost as driver-based or inflation-based depending on how it actually behaves. The same account can take a different treatment in different scenarios. For example, a cost might follow a driver in the near-term forecast and an inflation index in the outer years, where detailed operational drivers are less reliable.

That flexibility matters because mine plans rarely hold still. Commodity prices shift, production schedules change, and operating assumptions evolve. A model with only one cost treatment forces planners to work around it every time one of those changes.

Start From the Forecast, Not a Blank Sheet

LOM scenarios start from existing budget and forecast scenarios. Established assumptions carry forward, so planners focus on what has changed rather than rebuilding what hasn't. Actuals feed the same planning structure, which keeps reported and planned results consistent.

The result is less duplication, fewer disconnected planning processes, and a direct line from this year's forecast to the long-range plan. When someone asks why the outer years look the way they do, the answer traces back to assumptions finance already owns.

Where This Has Limits

OneStream does not replace specialized mining systems. Mine scheduling, geological modelling, reserve estimation, and production planning tools remain the operational source of truth. Their job is to define how the mine will operate. OneStream's role is different. It translates those operational assumptions into financial outcomes and connects them to budgeting, forecasting, reporting, and long-range planning.

Success depends as much on governance and ownership as on technology. Teams need clear answers to practical questions: who owns each assumption, how often operational updates move into the financial model, and which version of the mine plan is current. Without those answers, a connected platform just moves the inconsistency somewhere new.

What Finance Gains

When LOM planning and budgeting share one planning environment, a change to a production assumption flows through forecasts, long-range plans, and reporting from the same source.

A revised production schedule should not require finance teams to separately update forecasts, capital plans, impairment models, closure estimates, and supporting spreadsheets. Planning scenarios stay connected and draw from the same underlying assumptions.

That changes the conversations finance has with the rest of the business. Capital requests, impairment tests, and closure provisions rest on one set of numbers that ties back to the operating plan. Auditors and boards see consistent assumptions across short- and long-range views.

For finance leaders, that consistency is as valuable as the plan itself.

Life of Mine Planning with Ascend Partners

Ascend Partners has completed more than 700 OneStream implementations, helping numerous mining organizations unify planning, reporting, and performance management. The on-demand webinar walks through the framework in detail, from scenario design and flexible planning horizons to switching cost treatments between scenarios. 

If your LOM plan and budget operate in separate systems today, we'll share what we've seen work, where organizations typically struggle, and how others have kept long-range and financial planning aligned. Get in touch today.

About Ascend

Ascend Partners is the diamond standard in financial & data transformation solutions and proudly serves clients globally from our headquarters in New York, NY. We specialize in delivering sophisticated solutions that streamline financial workflows, transform data, and enhance operational efficiency for organizations worldwide. With deep industry expertise and a commitment to innovation, Ascend empowers businesses to maximize performance, improve decision-making, and drive sustainable growth.