What is SimSched Direct Block Scheduler?
SimSched DBS is a plugin software that uses innovative technology for Direct Block Scheduling. SimSched aims to maximize the Net Present Value (NPV) of a project deciding, based on an imported block model, which blocks will be mined, when, and to which destination they must be sent.
SimSched allows you to define multiple processing plants, stockpiles and waste dumps, respecting their capacities. You can also set physical limits or force mining in certain regions by importing surfaces.
The following video shows an introduction to SimSched, approaching technical concepts from Engineering.
What is SimSched Pit Optimizer?
SimSched PO is the only tool on the market able to perform pit optimization, aiming to maximize the undiscounted cash flow and choosing, among multiple destinations, which one is the best. Because PO considers blocks' values to make this decision, cut-off grades are a dynamic consequence of the process.
PO also respects minimum bottom width during the optimization. This tool surpasses those using algorithms that disregard economic aspects. Furthermore, the generated pit surfaces do not have geotechnical glitches.
PO is a free tool and, as it is a simplification of DBS, it is not our main focus of development. The video below shows a demonstration of SimSched PO.
What about SimSched Pit Optimizer Full?
SimSched PO Full is the first commercial tool able to perform pit optimizations that not only maximize the undiscounted cash flow but simultaneously defines cutoff strategies, respecting blending constraints, bottom width, controlling deforestation areas*, production by rock type*, metal production*, consumption of processing inputs*, forcing and/or restrict mining areas, among many other restrictions.
PO Full is a paid and affordable tool for pit optimization that covers a wider range of variables in its framework, giving you the opportunity to stick with the traditional approach while increasing its power.
* Check Other Constraints.
What are the differences between DBS and PO?
SimSched DBS considers the impact of money over time, by applying a discount rate, while aiming to maximize the NPV. SSDBS generates a sequence of extraction.
SimSched PO relies on the assumption that a deposit can be entirely mined at once. As a consequence, SSPO maximizes the undiscounted cash flow, finding a destination for each block.
This simplification was required in the past due to limited processing power, requiring a step-wise procedure. The downside of slicing a big problem into small ones is the fact that: (1) we blind ourselves from value-based solutions that would be feasible under a global perspective; (2) it takes longer to find a solution as each step depends on a previous one; (3) more time spent on each scenario means fewer scenarios tested.
What are the advantages of DBS over PO?
- DBS maximizes the NPV: DBS performs an optimization simultaneously to the scheduling, defining a sequence of extraction that covers the entire life of mine.
- Scheduling in a single-step: straightly from the resource block model to the scheduling results.
- Global View: DBS considers a wider range of constraints at once, supporting decision-making at many levels. This global view, along with the higher productivity, increases the capability of testing the merits of distinct assumptions and conjunctures, which in turn is important to define profitable strategies. The increased number of constraints within this advanced optimization process is the responsible for making this comparison possible in reasonable time. Now, assumptions do not need to consist only of economic aspects but mining variations as well.
- Uncertainties upon an ore body are an inherent risk from mining due to its punctual information. DBS can also use stochastic models to handle geological uncertainties, providing results along with risk-profile.
- Manipulations are now executed after the optimization. Advantages of it:
- Time cost: manipulations, adjustments, and pit designs can now be postponed, applying them only to the best scenario. Thus, it makes possible to run more scenarios because the user will no longer need to manipulate each one of them to decide, among feasible and operational scenarios, which one is the best.
- Fair comparisons: manipulations are never the same as we cannot reproduce them for different scenarios. Manipulated surfaces can be used after the scheduling, for all the secondary scenarios the user wants to update, so manipulations will be exactly the same to test different assumptions.
- Productivity: SimSched gives to the user the possibility of being opened in different instances. The more powerful is the machine, the more scenarios the user will be able to run simultaneously.
- And more: DBS has the same advantages PO has over LG. Check the section What are the advantages of PO over LG? below.
What are the differences between PO and the Lerchs-Grossmann pit optimization?
Lerchs-Grossmann algorithm has been an intelligent approach to solve the mining problem by breaking it into pieces. However, it is still an incomplete answer, blind to other mining considerations. SimSched PO is an alternative to such challenges by taking control of more constraints.
What are the advantages of PO over LG?
- PO maximizes the cash flow: it is not required to select a nested pit, even though the user is able to do so for very specific reasons.
- Cut-off strategies are now a consequence of maximizing the cash flow: it is not necessary to define a cut-off grade as it does not make sense anymore.
- Bottom widths are respected and make the pits more operational. This could also be an advantage to define pushbacks (phases).
- Surfaces are used to restrict mining in a specific region and to force mining in other portions of the deposit.
- (PO Full) Blending constraints are now considered during the pit optimization.
- (PO Full) Other constraints make the user able to consider any summed parameter as a limit.
- Rock type and/or metal production: the user is able to define productions and/or proportions regarding different lithotypes and/or elements.
- Consumption of processing inputs: the user is able to consider the amount of energy used during the comminution, fleet hours spent to mobilize material, and basically any quantifiable information the user is capable of assigning to each block.
Differences in a nutshell!
The following table summarizes the comparison across all versions of SimSched, according to the features available for each version.