Analysis Tools
Vensim Analysis tools fall into two broad classes: tools for structural analysis, and tools for dataset analysis. Structural tools allow you to investigate the model structure; dataset tools allow you to investigate simulation datasets to determine the behavior of variables. In this section, we will analyze the structure of our model. Structural Analysis tools include the Tree Diagram tool (Causes Tree and Uses Tree), the Loops tool, and the Document tool.
Analysis tools almost always work by generating information about the Workbench Variable. You select the Workbench Variable by one of two methods. The easiest method is to click on the variable, wherever it appears. The variable is usually somewhere in one of the sketches, unless the model is text-based. You can also click on a variable in an Output window, such as a Tree Diagram or a Strip Graph. The second way to select a variable into the workbench is to click the Control Panel button to open the Control Panel, select the tab Variable to open the Variable Selection Control, then choose the variable from the list. The Workbench Variable always appears on the title bar of the model.
NOTEIf you activate an Analysis tool that requires a simulation dataset, and you have no simulation dataset loaded, you will see the message "No runs are loaded. Please load runs". This tells you that you need to run a simulation. Chapter 6 will describe how to build a simulation model.
EITHER
| Ø | Use the model project.mdl that you just built, |
OR
| Ø | Open the model project.mdl in the UserGuide\chap04\complete directory. |
| Ø | Select the Lock tool. Now move to the variable Work To Do and click on it to select it as the Workbench Variable. The title bar should look like: |
