Surface Priorities
The combination of precedences and priorities determines the mining sequence. Precedences define which locations must be mined before other locations are available to be mined. Priorities determine which location is mined first when multiple locations are available and quality or material ratio targets have not been defined.
If quality or material ratio targets have been defined, the mining sequence is chosen to best achieve the targets. However, priorities still play a role in the selection of locations when all of the material available is the same. For example, when determining which locations to mine when only waste material is available in all locations.
Two priority data grids exist for Surface scenarios. You use the Initial production priorities data grid to define the priority of the locations at the start of the schedule. You use the Production priority changes data grid to define the changes to the priority of locations at different dates, or after events have occurred during the schedule.
Note: If you define priorities in the Production priority changes data grid that are effective from the start of the schedule, they override the priorities you set in the Initial production priorities data grid.
You can define initial production priorities using the data grid or you can use the spreadsheet view by clicking the Edit in spreadsheet view icon.
Note: The spreadsheet view for the Initial production priorities data grid is temporary. When you click OK or Cancel, the values in the spreadsheet are saved as text in the data grid. This means that any additional data and the formulas you used to create the priorities are not maintained.
You can define the production priority changes in the data grid or you can use the spreadsheet view. To access the spreadsheet view, select Spreadsheet > Enable Spreadsheet Views, and then select the Priorities spreadsheet. When the Priorities spreadsheet is enabled, it replaces the Production priority changes data grid.
Columns in the Initial Production Priorities Data Grid
| Column | Description |
|---|---|
| Active |
|
| Location |
The name of the location to which the priority is applied. |
| Priority | The value of the priority for the location. Values can be any number greater than zero. The lower the number the higher the priority. |
| Comments | Any notes you want to record about the priority. |
If you want to define more than one level of priority, use the Settings icon at the top of the Initial production priorities data grid to create columns for different levels of priorities. When you click the Settings icon the Priority Levels form appears, which displays the Priority levels data grid.
Columns in the Priority Levels Data Grid in the Priority Levels form
| Column | Description |
|---|---|
| Name |
The name of the priority level. The name of the first priority level is set by default and cannot be changed. You can change the names of subsequent priority levels.
|
Columns in the Production Priority Changes Data Grid
| Column | Description |
|---|---|
| Active |
|
| Locations |
The location or locations to which the priority is applied.
|
| Resources |
The name or names of the resources to which the priority is applied for the location.
|
| Date/event |
The date on which the priority change is applied to the location or locations. You can use a calendar date or an event. The date or event plus the Delay determines the actual start date. You use the Calendar button to select a date from a calendar. You use the Ellipsis button to select an event using the Event Builder. |
| Delay |
The delay after the Date/event before the priority change is applied to the location or locations. The default delay is 0. The delay can be any positive number.
Usually, delays are used when the Date/event is an event, and the actual date that the event occurs is not known until the schedule is run. |
| Priority |
The value of the priority for the location or locations. Values can be any number greater than zero. The lower the number the higher the priority. |
| Comments | Any notes you want to record about the priority. |