UDESS is a tool developed in Delphos with the initial motivation for planning, simultaneously, production and construction of block and panel caving mines. This stems from the concern that, when undertaken in stages (first production and then construction) inefficiencies occur in the final result, which may be suboptimal or even infeasible.
This is represented in the figure below, where it is outlined, in simplified form, the standard planning of block and panel caving mines. In this approach, first a production plan is constructed from the scheduling of extraction activities (left). This induces requirements on the layout, for which a construction that seeks to meet the production plan is schedule(right).
In the case of the methodology proposed by UDESS, both plans are computed simultaneously, ensuring that the production plan is backed by one of mine preparation, as outlined in the following figure, where has been included more activities downstream , such as building a shaft or crusher inside the mine.
UDESS operates under the paradigm of activities which, when executed, consume certain resources and represent a benefit or cost. Examples of activities are:
- Extraction from a stope
- Backfilling a stope
- Extracting a portion of a column in a caving mine.
- Extracting a polygon or bench in a pit.
- Construction of an extraction point in a caving mine.
Furthermore activities are linked together by precedence, since it effectively is not possible do some of them without having achieved others. Thus, considering the previous examples of activities; backfilling a stope is preceded by extraction, and the extraction of a mineral column can only occur after the construction of the respective points of the shafts, among others.
UDESS take the above information and generates a "Gantt chart" of activities, which specifies for each period the percentage of this activity to be carried out so as to maximize or minimize an objective function as the NPV or costs. You can also use UDESS to minimize construction time of a project.
UDESS planning tool has a graphical user interface (GUI) that allows, in simple form, creating a project, definition of parameters to consider, generating precedence and export to text files or Excel.
Block Caving and Panel Caving Planning
UDESS has been successfully used to generate production plans of block caving and panel caving mines and, at the same time, schedule the construction of them . This also generate production plans that respect all mine production capacity and has the advantage that it is possible to ensure constructability of the project.
The figure below shows a comparison of a plan obtained by UDESS and another tool. The UDESS plan adheres to better production restrictions and also has a associated preparedness plan.
Sublevel Stoping Mine Planning
UDESS has been used to plan selective underground mines. In this case the activities correspond to the construction of tunnels and drifts, and the extraction and filling of stopes. Thus, UDESS is able to model the operation of a mine, for example bench & fill or sublevel stoping to generate a coherent plan with directions extraction, but that makes the best use of installed capacity and resources (production capacity, filling ability, etc.).
Open Pit Mine Planning
As UDESS works with generic activities, you may also use it for scheduling of production in open pit mining. In this case the activities are, for example, parts or entire benchs and precedence can be used to model minimum and maximum distances between consecutive phases, generating scheduling style Milawa NPV, but balanced according to capacity constraints defined by the user.
UDESS and planning under uncertainty
As UDESS enables automatic scheduling of fast running time, it has also been used to study the sensitivity of the plans against price and geological uncertainty.
