Life-of-Mine Planning

Life-of-mine (LOM) planning establishes how a mineral asset could be developed, operated and brought to the end of production under a stated set of assumptions. It connects the material available for extraction with the mining approach, processing route, infrastructure, investment and obligations that make production possible. Its central question is whether those decisions form a coherent strategy over the remaining life of the operation. Long-term planning therefore connects strategic choices with operational delivery and feedback.^[1]

A production schedule is one component of this plan. A schedule can allocate tonnes successfully while relying on an unbuilt facility, an unsupported geological assumption or an unfunded expansion. The LOM plan makes those dependencies visible so that the scheduled outcome can be assessed as an engineering and investment proposition.

Define the Planning Boundary

State the asset, starting condition and decision being evaluated. A new project starts from a different position from an operating mine with completed excavations, existing stockpiles, committed contracts and aging infrastructure. An expansion assessment must identify which facilities and costs belong to the existing operation and which arise from the proposed change.

The end date also needs a definition. Mining may finish before stockpile processing; commercial production may finish before water treatment or monitoring. ICMM's 2025 closure guide distinguishes the productive life of mine from the life of asset, which includes the post-closure period. A plan can therefore finish its production schedule while retaining a longer assessment of liabilities, services and expenditure.^[2]

Describe what remains outside the evaluated boundary. Purchased feed, off-site transport or a shared treatment facility can be essential to the outcome even when another party operates them. Their capacity, availability and commercial assumptions still require an explicit interface with the plan.

Establish a Traceable Inventory and Design Basis

The quantity in a geological model is not automatically the quantity that can be mined, processed or sold. Under the Canadian CIM 2019 estimation guidance, Mineral Reserves require modifying factors, mine designs, production schedules and economic evaluation within at least a prefeasibility study. Inferred Mineral Resources cannot be converted directly to Mineral Reserves; the guidance treats them as waste in the reserve-supporting mine plan. Keep internal scenarios that assume their future upgrading distinct from the Mineral Reserve case.^[3]

For each planning case, identify the resource model version, confidence categories included, extraction limits, mining losses, dilution, recovery assumptions and material destinations. State whether reported tonnes refer to material in place, mined feed, processed feed or product. Otherwise a change of reporting basis can look like an improvement in extraction or recovery.

For an operating mine, the opening position must reconcile with what already exists. CIM's LOM design guidance starts updates from current excavation models and designs, then considers changed inputs and newly identified mineralization. It also separates mathematical extraction envelopes from the engineering designs needed to support a mine plan.^[3]

An effective assumption register records more than a number. It identifies its owner, evidence, applicable area or period, uncertainty and consequences if it proves wrong. For example, a recovery assumption supported by test work on one material type should not silently extend to a newly included zone. The relevant question is whether the evidence supports the particular decision being made.

Compare Complete Development Strategies

Strategic alternatives should differ in meaningful choices: extraction extent, mining method, access arrangement, production scale, processing configuration or timing of a major investment. Changing only a financial assumption tests a different future; it does not create an alternative engineering strategy.

Evaluate each strategy as a connected pathway. A deeper underground extension can require access development before additional ore becomes available. An open-pit expansion can require waste removal before exposing its planned feed. The comparison needs the preparatory work, its timing and its consequences for the existing operation, rather than only the value of the additional material.

The following questions help expose incomplete alternatives:

These are engineering tests, not a ranking formula. An option can have attractive total inventory yet a difficult transition between existing and new production. Conversely, a modest extension can use existing facilities efficiently but leave little flexibility if its expected feed proves unavailable.

Connect Production, Infrastructure and Expenditure

The plan should show when material becomes accessible, when each destination can accept it and when the required services become available. This is the bridge between a production profile and its enabling investment. CIM describes production schedules as the basis for estimating capital and operating costs and forecasting saleable output.^[3]

Use milestones to test the bridge. A production increase assigned to a period needs an accompanying explanation of which construction, commissioning, recruitment or development activities have been completed. If a facility is available partway through that period, its usable capacity cannot be represented by a full period of unrestricted operation.

Infrastructure also has a spatial history. A transport route that works early in the mine life may be displaced by later extraction. A permanent installation can sterilize an intended expansion area. Compare alternatives using the layout at relevant stages, including temporary arrangements and replacement routes, rather than checking only the final geometry.

Check the decline in activity as carefully as the increase. When production contracts, the remaining operation may still require substantial services. Extending the calendar duration can therefore add expenditure without proportionately adding product. Equipment replacement and other sustaining investment must be assessed against the actual period of required service, including any use after production.

Use a Consistent Economic Basis

Commodity prices and exchange rates are assumptions with a time context. CIM's 2020 commodity-pricing guidance discusses several supportable methods without prescribing a universally preferred one. It recognizes that the expected start of production can affect the appropriate price basis and that exchange-rate assumptions should be considered alongside commodity prices. The selected approach and rationale need to be disclosed in its Canadian resource and reserve estimation context.^[4]

For strategy comparison, use a common valuation date, currency basis, treatment of inflation and scope of costs. Identify whether figures include taxation, royalties, sustaining investment and closure expenditure. A difference caused by inconsistent accounting boundaries should not be interpreted as an engineering advantage.

Timing matters independently of total output. An option requiring substantial early development commits funds before its products can generate revenue. Deferring that development changes both expenditure and access to future production. Compare the resulting cash-flow paths, capital exposure and operational consequences together; an attractive discounted value alone does not explain whether the required funding or implementation pathway is credible.

Integrate Closure While Options Remain Open

ICMM's third-edition guide treats closure as an input to short-, medium- and life-of-mine planning. It identifies opportunities to incorporate final landforms, progressive closure and material placement into operating decisions, and calls for coordination between planning, environmental and community functions. This is good-practice guidance rather than a substitute for the requirements applicable to an individual site.^[2]

The practical implication is to test whether today's layout preserves tomorrow's intended closure outcome. If a proposed storage area occupies a future access corridor, either the operational strategy or the placement strategy must change. If a facility will be needed for post-production water management, its retirement cannot be tied automatically to the last extraction period.

Closure assumptions also require a credible fallback. A plan that depends on completing all progressive rehabilitation before an expected final year should examine what happens if production stops earlier. That test can reveal commitments that otherwise remain hidden beyond the selected production schedule.^[2]

Test Uncertainty and Preserve Useful Choices

Kloppers and colleagues describe scenario planning as a way to compare alternative strategies under different internal and external assumptions. Their Lonmin example links this work to operational feedback and formal review. Its particular annual cycle is an organizational arrangement, not a universal planning interval.^[1]

Separate three questions. Sensitivity asks how an outcome changes when an assumption changes. A scenario combines assumptions describing a possible future. A response strategy identifies what the mine would do if that future developed. A sensitivity curve does not assign probabilities, and independently choosing the best plan after each future is known overstates the choices available before investment.

For a qualitative example, suppose investigation indicates that a planned extension will take longer to access. Recheck the feed available during the delay, the timing of processing expansion, shared service demands, expenditure before revenue and the proposed production end date. Alternative feed may bridge the gap, but only if its access, processing suitability and opportunity cost are also examined. No single adjustment to the headline annual tonnage resolves all these dependencies.

Govern Revisions and Explain the Change

Keep a controlled baseline and distinguish a forecast update from a decision to change strategy. Actual depletion, new drilling, revised engineering or changed markets can each justify revision, but they have different meanings. Retaining the previous model and assumptions allows the effect of new knowledge to be separated from deliberate changes in operation.

A useful comparison explains changes in inventory, extraction geometry, production timing, enabling projects, expenditure and residual obligations. It should identify which decisions remain reversible and which have already been committed. A cheaper future option has little practical value if the current layout has removed the access it requires.

The reviewed plan becomes a set of requirements for more detailed schedules and project decisions. When those schedules reveal that a milestone cannot be met, the issue must return to the LOM assessment. Maintaining this connection keeps the account of the mine's development consistent with its demonstrated ability to deliver.