Run your case

Run types

You can run your cases in several different modes. These modes determine how material is routed through the flowsheet, either in a fixed manner (determined by you), or in an optimum manner determined by the constraints of the case.

• Simulate: Simulates the flowsheet pushing fixed amounts of feedstock through the units in a feed-forward manner.

• Optimize: Optimizes the flowsheet, varying the purchase of feedstocks to maximize the profitability of the plant within the bounds of any constraints applied to the model.

The Optimize mode appears only if you have a valid Spiral Plan license.

For more information about checking for installed licenses, see the Configure your Licenses topic. Contact AVEVA support (spiral.support@aveva.com) for information about obtaining new licenses.

After running the model, results for the model performance (including if any part of the optimization failed) are reported in the Metrics window.

You can use the following keyboard shortcuts to optimize your case:

• Ctrl + R runs the optimization. Equivalent to clicking the Run button in the Modelling group of the Home ribbon tab, with the Optimize option selected.

• Ctrl + Shift + R forces the optimization to run even if the results of the previous optimization are still up to date. This can be useful, for example, if you are diagnosing a problem and need to run an optimization multiple times.

When you optimize a Plan case, assay recutting is automatically triggered if needed. When you optimize a Network case, the same happens for all embedded plant cases. This ensures that all optimizations use the latest available assay data.

Note that assay recutting is not automatically triggered when optimizing Network analytic cases.

While a case optimization is running, you are prevented from editing any other open instances of that case or any of its parent cases. This is to prevent any changes from interfering with the optimization.

This also applies to case stacks: if one of the cases in a stack is being optimized, the case stack is locked.

See this topic for how to publish your case data to file after optimization.

Find how much material flows through your process units

After optimization has completed, you can find the flows through each of your process units by clicking Connectivity in the left pane.

The Connectivity grid also shows how units are linked together. The row names show the names of the process units and the output streams from each unit. The column headers show the process units in the flowsheet.

If one or more of the streams in the flowsheet is not directed to a different unit or a sales pool, the flow is shown in the Unconnected flow column as well as the standard flow list.

From the Flow Type drop-down menu at the top of the page, you can choose which type of data to show:

• Amount: Shows the amount of material flowing in each stream in or out of the process unit. Choose between weight-based and volume-based units from the Flow Amount Unit drop-down menu, and choose the exact unit from the UoM drop-down menu. You can use this to check for any unused material in the Unused column.

• Direction: Shows whether the stream is feeding In to the unit, or Out from the unit.

  Tip: Filter the list via the Filter menu and configure which columns are shown, and in what order, via the View menu. See the Grids topic for more information.

Fix and lock your constraints

The Constraint Activity window toggles the Fixed or Locked status of constraint values in the Plan case. The different types of constraints are separated into Constraint Groups, and for each constraint group the currently configured Fixed or Locked status can be overridden by selecting or clearing the corresponding check box.

• Fixed: Allows you to define a particular value that you wish to obtain, and the model will optimize to match this specific value.

• Locked: After optimization, you can lock down a solution of a particular constraint, in order to keep that value when you next optimize.

  

  Tip: The Fixed column is visible only when the Optimize button is active in the Modelling group of the Home ribbon tab.

  

Where both check boxes are inactive, all the Fixed statuses are deactivated, and the solution values are not locked.

When the Fixed option is selected all the Fixed statuses for that constraint group are activated.

When the Locked option is selected, all the solution values for that constraint group are locked.

When both options are selected, the Locked option overrides the Fixed option, so all the solution values for that constraint group are locked.

When only some of the Fixed check boxes for a group are active, the constraint group check box is displayed with a .