The global data item Overhead Cost is created by Simul8 automatically. You can attach costs to every object in your simulation, overhead costs allow you to specify additional costs not triggered by work items passing through simulation objects. For example, you may have capital costs if this is a greenfield site that you wish to include.
The value of Overhead Cost cannot be read or set via the Information Store, it can be changed and read through Visual Logic.
To manually set starting values for overhead costs, or to change these without using Visual Logic, see Overhead Costs and Revenues