MFO Essentials

In addition to all MAO functions, Mine Flow Optimizer (MFO) maximizes NPV by adjusting up mining rates (cutoff grades are also optimized).

Note: Mine Flow Optimization is fully integrated in Studio NPVS+ meaning a separate MFO optimization isn't required. As such, this module does not appear in Studio NPVS+.

MFO Objective and Process

The goal of MFO is to determine yearly mining rates (X₁, X₂, X₃, …) that maximize Net Present Value (NPV) over the mine’s life. If NPV = F(X₁, X₂, X₃, …), MFO seeks the maximum of function F.
Since F has no gradient, it must be evaluated at many points. Each evaluation requires solving the MAO problem.
Studio NPVS uses an efficient method (similar to the golden section algorithm) to minimize the number of evaluations needed.

How MFO Adjusts Mining Rates

If X₁ (Year 1 mining rate) increases by 100,000 tonnes, MFO reassigns blocks from Year 2 to Year 1 to meet the new target.
To balance this, blocks from Year 3 are moved to Year 2, and so on, cascading adjustments through the schedule.
After updating inputs for all years, MAO is run to calculate the new NPV.

Additional Considerations

If capital costs depend on mining rates, MFO adjusts their timing accordingly.
All calculations are based on the OES.
Stockpile impacts are fully accounted for.

Conclusion

MFO completely dispenses with the old “cutoff grade optimization” logic that is unsuitable for multiple products and does not account for stockpiles.
The logic is simple and accurate.
It takes into account the sequence in which the blocks are likely to be mined.
It fully accounts for the impact of stockpiles.
It fully accounts for capital costs.
It works for any number of products and processing methods.
It is faster to process
The output is the MAO type parcel model with the extraction time and destination fields.