Maximum Active Benches

It is advisable to limit the number of benches per stage mined at a given time to save costs and ensure safety.

Use the Maximum Active Benches constraint to restrict the number of benches in a stage being mined simultaneously in a single period.

Note: If you apply this constraint, you cannot apply the Stage Bench Turnover constraint.

To configure this constraint:

1. Click on a cell in the table which will belong to a particular pit, stage, and period.

2. Enter a value. This will represent the maximum number of active benches in that period. In the image below, we edit the maximum active benches in stage 8 of the pit Au_demo_new_phase in Period 1. This means that the maximum number of benches that can be mined at the same time in period 1 for stage 8 is 3. Note that this is different from limiting the total number of benches mined in a period. In other words, for this example, you can mine more than 3 benches in period 1 in total, just not at the same time.

   

After you generate a schedule, you can see if the constraint is being honoured in the Schedule Viewer or by exporting the schedule as a CSV file. To do this, right-click the schedule in the Data Explorer and select Export block data to CSV.

How you construct your spreadsheet will depend on the program you are using. Here is a basic overview of how to set it up:

1. Obtain a list of unique benches.

2. For each unique bench, find the rank of the first mined block.

3. For each unique bench, find the rank of the last mined block.

4. At each rank, for each bench, work out whether the rank falls between the values calculated in steps 2 and 3. If the rank falls between the values calculated at steps 2 and 3, that means that the bench is active. If the bench is active, you can add it to your tally.

5. Graph the number of active benches calculated per rank. Your graph should look something like this.