Capex & Equipment Lifecycle Model
This use case explains how to model capital expenditure, equipment fleets and lifecycle costs for mining, energy and natural resources organisations in Model Reef.
You will:
Represent major capital items and projects as Asset variables.
Plan initial capex, sustaining capex and replacement programmes over time.
Model equipment operating costs and productivity links.
Connect capex and lifecycle assumptions to depreciation, cashflows and valuation.
Model Reef is not a maintenance management system. It focuses on financial planning for capex and equipment, not detailed work order scheduling.
When to use this pattern
Use this pattern when:
Your business relies on heavy equipment, plants, pipelines or infrastructure.
You need to understand timing and magnitude of capex and replacement cycles.
You want to compare different fleet or plant strategies.
You must show lenders and investors a coherent capex plan alongside production.
It is commonly paired with:
Mine or Well Production Forecasts
Commodity Price Sensitivity
Multi-Site Resource Consolidation
Architecture overview
Define asset classes and branches
In the branch tree, decide where to hold equipment and infrastructure capex, for example:
Mine - Open Cut A
Assets - Mobile Fleet
Assets - Fixed Plant
Mine - Underground B
Assets - Mining Fleet
Field - Gas C
Assets - Well Infrastructure
Central Infrastructure
Assets - Shared Rail & Port
Alternatively, store all capex in the site branch without sub-branches and use categories to separate asset types. The choice depends on how you want to report and analyse.
Set up opening balances for existing assets
For existing operations, import or enter:
Opening asset balances by class, aligned with the latest Balance Sheet.
Remaining useful life estimates or depreciation rules.
Any major deferred projects already committed.
Represent these as Asset variables with:
Opening balances.
Depreciation methods (for example straight line).
Remaining life inputs where supported or approximated.
This ensures the model starts from a realistic asset base.
Plan initial, sustaining and growth capex
Create Asset variables for planned projects, for example:
Capex - Replacement Trucks - Mine A.
Capex - New Processing Line - Mine B.
Capex - Pipeline Expansion - Field C.
Capex - Control Systems Upgrade - Shared Infrastructure.
For each, specify:
Total capex budget or unit cost per item.
Timing profile across periods, such as upfront, phased or milestone based.
Expected useful life and depreciation method.
Whether the project is sustaining (replacing life expired assets) or growth (increasing capacity).
Use drivers to represent fleet strategies, for example number of units and replacement intervals, so scenarios can vary:
Fleet size.
Replacement timing.
Mix of new versus refurbished assets.
Link capex to production capacity where needed
Where production depends on equipment capacity, create drivers such as:
Capacity per Truck.
Capacity per Processing Line.
Relating fleet size to maximum throughput.
Use these drivers in production models to ensure:
Insufficient fleet or plant limits production.
Additional capex unlocks higher throughput or reduces unit costs.
Deferred capex may constrain volumes or increase operating risk.
Keep this linkage as simple as possible while still capturing the main relationships.
Model operating costs and lifecycle impacts
Create Opex variables for equipment related operating costs, for example:
Opex - Maintenance - Mobile Fleet.
Opex - Fuel & Power - Plant A.
Opex - Tyres & Wear Parts.
Opex - External Repairs.
Link these to drivers such as:
Hours used per period.
Production volumes.
Fleet size or age.
You can reflect lifecycle effects by:
Higher maintenance cost factors for older fleets.
Reduced availability or uptime multipliers.
Step changes in cost structure when new equipment is commissioned.
This enables comparison of strategies such as run-to-failure versus systematic replacement.
Include rehabilitation or decommissioning provisions
For mines and some energy assets, include:
Asset or Liability variables for rehabilitation provisions.
Cash outflows for rehabilitation activities near or after closure.
Depreciation or unwinding of provisions depending on accounting policy.
While Model Reef does not perform full provision accounting, you can approximate expected cash and P&L impacts at life-of-asset end.
Use scenarios for capex strategy and timing
Clone the model into scenario models to test:
Different fleet replacement intervals and sizes.
Deferral or acceleration of major projects.
Alternative processing routes or plant configurations.
Changes in cost and productivity associated with new technology.
In each scenario, adjust:
Timing and scale of capex variables.
Operating cost and productivity drivers.
Production forecasts where capacity is constrained or increased.
Compare scenarios using:
Capex and operating cost per unit of production.
Cashflow and funding requirements.
Valuation outcomes from the Valuation Engine.
Risk profiles associated with deferred maintenance and replacement.
Check your work
Opening balances and depreciation reconcile to recent financial statements.
Planned capex and lifecycle assumptions are aligned with internal maintenance and growth plans.
Operating cost patterns are consistent with historical data.
Scenario comparisons reflect realistic operational choices and constraints.
Troubleshooting
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