Constraints

Source file: origin-reserve-setups-constraints.htm

Constraints provide you with advanced ways to refine data.

Click Constraints > Overview on the setup configuration tab to view the constraints available for your setup. Each constraint tile includes a short description.

You can apply required constraints by clicking (Add new constraint). The constraints applied to your setup will appear on the left side of your screen, as well as under the Constraints configuration drop-down.

Constraint detailed setting screen can be entered either by:

  • Clicking on the required constraint in the Applied Constraints list.

    Or

  • Selecting the required constraint from the Constraints tab drop-down.

The following buttons appear on all constraints to provide unified and simplified ways of operation:

Enable or disable constraint
Toggle button that allows you to enable or disable a constraint in your setup.

Delete constraint
Removes constraints from your setup.

Edit constraint name
Allows you to rename a constraint.

To rename a constraint do the following:

  1. Select the constraint whose name you want to change and click the (Edit constraint name) button. The constraint name will become editable.

  2. Enter the new name and click .

    The new constraint name will be applied in the constraint main page and on the list of constraints applied in your setup.

    Note:  The default constraint name, which indicates the type of a constraint, will remain unchanged and will still be displayed in grey colour under the changed name on the Applied Constraints list.

Clear the selected cell
Erases the data from the selected cell.

Overview
Goes back to the Constraints Overview screen.

The following table provides a description of each constraint available in Origin Solids setups.

Constraints are classified as Hard and Soft, with the following distinctions:

  • Hard constraints are mandatory for Evolution when it determines a schedule.

  • Soft constraints are taken into account by Evolution when it determines a schedule, but meeting them is optional.

Constraint Type Description
Bench Accumulation Hard Sets the maximum amount that can be mined per bench per period.
Global Accumulation Hard
(for maximum),
Soft
(for minimum)		 Sets a maximum/minimum volume or amount of tonnes that can be mined per period.
Global Process Accumulation

Hard
(for maximum),
Soft
(for minimum)

 Sets a maximum/minimum accumulation that is moved from any pit, to any mill in a setup per period.
Pit Accumulation Hard (approximate) Defines the maximum volume or amount of tonnes that can be mined per pit per period.
Parcel Waste Destination Priority Hard Sets a priority order of waste areas for each parcel in the setup.
Pit Region Availability Hard Sets the mining availability of areas in each period. Typical regions used include bench or stage.
Pit Region to Waste Region Hard Maps regions in the pit to regions in the waste utility.
Process Accumulation Hard Restricts the maximum amount of material a mill can process per period (tonnage or volume).
Sink Rate Hard (approximate) Calculates the mining duration per bench, based on the total tonnes available for mining on a bench and the corresponding dig rate.
Stage Accumulation Hard (approximate) Restricts the amount of material (tonnage or volume) that is mined per stage in a pit per period.
Stage and Waste Utility Dependency Hard Assigns dependencies between the stages and waste areas.
Stage Availability Hard Flags the availability of stages for mining per period.
Stage Bench Turnover Hard Sets the maximum number of benches that can be mined in each stage per period.
Stage Dependency Hard Defines the mining order of stages.
Stage Equipment Hard Maps equipment to specific stages in a pit.
Stage Sink Rate Hard (approximate) Sets the maximum sink rate allowed for each stage in each period.
Stockpile Reclaim Availability Hard Sets the period in which the material can be reclaimed from a stockpile.
Stockpile Redirect Availability Hard Specifies the periods in which the stockpile material can be redirected to a mill.
Waste Area Availability Hard Sets the availability of each waste area for waste dumping on a periodic basis.
Waste Area Dependency Hard Specifies dependencies (usage order) between waste areas.
Waste Area Rate of Rise Hard Limits the number of active benches per waste area in each period.
Waste Area Required Tonnage Soft Sets the maximum amount of waste that can be dumped per area in a period.

Approximate constraints

The Evolution engine determines the sequence of solids to be mined (for example, A, then B, then C). No solid constituting this sequence can be split and interspersed among other mined solids. For example, if separating solid A was inevitable, it would still need to be mined sequentially (A (part 1), then A (part 2), then B, then C), and interspersing it among other solids (A (part 1), then B, then A (part 2), then C etc.) would not be possible.

Consequently, in order to meet the period targets and maintain a single mining sequence, the solid should be split at the end of a period. This split criterion affects the constraints that limit the amount of material taken from the pit.

For example, if Stage Accumulation constraint sets the stage A mining limit in period 1 to 1000 tonnes, but a solid weighing 1500 tonnes was mined in that stage, then the exceeding value would be recorded and the mining from that stage would be stopped.

It is recommended that models be composed of multiple small solids. This will help the constraint limit be achieved more closely, as an approximate hard constraint can only ever be exceeded by a portion of one solid.

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