Manage demand groups

The Demand Groups page defines the groups that demands can belong to. You can also add sales from associated plant cases to demand groups.

Hierarchy. You can group demand groups together, thereby creating a hierarchy of groups. For example, a group of gasoline demands and a group of diesel demands can themselves be added into a group, and the ratio of gasoline to diesel defined. In the Group column, you can select a group to act as the parent of any other group.

Pro Rata. The check box in the Pro Rata column controls whether to pro rata the constraining amounts. When pro rata is active, the amount is divided across all periods equally (weighted with respect to period duration) so that demand is approximately equal in all periods. When pro rata is not active, the amount is aggregated across all time so the constraint will be applied, but may all be utilized within a small set of periods. See Optimization across and within Periods for more information.

Member Limit. If this Member Limit is set to a number N, then no matter how many crudes are in this group, the optimizer will pick the best solution containing at most N of those crudes.

Exchanges. You can link demand groups to supply groups to form part of an exchange arrangement.

Set up a group

1. Create the group

   1. In the Demand Groups tab, do either of the following:

      • Click Add Group in the Groups group of the Home ribbon tab.

      • Right click anywhere on the grid and choose Add Group from the context menu.

   2. Enter the desired name for the group in the Name column.

   3. In the Wgt/Vol column, choose whether the group is weight- or volume-based.

2. Add items to the group

   4. Go to the Demands tab.

   5. If you cannot see the Group column, select All from the View drop-down list in the Grid group of the Home ribbon tab.

   6. In the Group column, select the group you created for each supply you want to add to the group.

   7. Optionally, go to the Grouped Demands tab and enter a minimum, maximum or fixed constraint.

3. Review and edit the group

   In the Grouped Demands tab you can see a summary of those demand groups you have configured, together with the members of each group. You can edit details of group members in this tab, as well as add constraints, but you cannot create new groups, nor add or delete group members.