Incremental Blend

In the incremental blend workflow, you vary the amount of one of the crudes in your base blend by creating a number of scenarios in the Sensitivity page.

1. Review base blend

   In the Base Blend page, make sure that all the crudes you want to include in the base blend have the Active check box selected. Do not lock solutions: if any solutions are locked (padlock icon in the Parent Case Solution cell) select them and click Unlock Solution in the Behaviour group of the Home ribbon tab.

   You can retain, create, or deactivate constraints (in the Min, Max and Fixed columns) according to your requirements. You can also impose a constraint on the crude you want to vary. This constraint will be applied in the base scenario, but overridden in each of the sensitivity scenarios.

   

2. Review candidates

   You do not need to define any candidate crudes, since the crude you want to vary is already in your base blend. Check boxes in the Active column should not be selected.

   

3. Set up sensitivity scenarios

   Open the Sensitivity page and click on Add Items in the Sensitivity group of the Home ribbon tab. Add the crude you want to vary the amount of.

   Set the Number of scenarios value. Make sure that the Sensitivity Parameter column is set to Fixed. Enter a crude amount in each Scenario cell. Note that the unit of measure for these amounts is shown in the UoM column.

   

4. Review the case stack

   Open the Case Stack page and make sure that all the scenarios you intended to add are listed.

   

5. Run the optimization

   Click the Optimize button in the Optimization group of the Home ribbon tab. In the Case Stack page, the Alert and Status columns fill with the outcome of the optimization for each scenario. If the optimization is successful, the objective function value appears in the Objective Function column.

   

6. Review the optimization results

   Check the graphs in the Analysis section to review your results. Two examples are shown in the figures below:

   • The Economics Bar Chart page shows how the objective function varies across the scenarios. You can see at a glance which scenario produces the best results.

   • The Crude Mix Chart show the crude purchases in each scenario. You can see how the quantity of test crude (in this case Arab Light) varies across the scenarios, and how the quantity of other crudes changes as a result.