This article generally applies to iGrafx Process and iGrafx Process for Six Sigma Client tools where simulation is possible. Simulation reports, however, can be viewed by iGrafx FlowCharter users.
If you place your mouse over a statistic in the report, a "yellow tooltip" should give you a brief description of what the statistic measures. The tooltip does not tell you how the statistic is summarized (e.g. Avg vs. Tavg vs. Total), but instead simply what the unsummarized statistic is measuring.
Sometimes this brief yellow tooltip help is not enough. The best place to look for understanding the statistics that iGrafx generates is in the Help System, which contains all of iGrafx's User's and Reference Manual. To access the help, from the Help menu choose iGrafx Help. On the Search tab of the help, type in what you're looking for. For example, if you search on "Avg OOS", you'll get a listing on resource statistics.