Large models can be presented more clearly in multiple views than in a single view. Views can be thought of as similar to pages of a book, each page telling a portion of the story. Each view displays a sketch and is connected to one (or more) of the other views through variables or shadow variables. Multiple views allow models to be broken into sectors, such as production, financial, customer and so on.
Graphic Models and Variables
Vensim models are definitively expressed in equation or text form. A sketch or graphical view of a model might not show all of the variables present or all of the relationships among those variables. When sketching a new model, you add variables to a view. These variables can be removed (cut) from the view but still be present in the model. Variables and structure also can be hidden with the Magic Wand tool. Variables can be added directly to the model by using the Equation Editor (or Text Editor in Professional and DSS); these variables will not show on the sketch unless you add them (using the Variable tool) or Vensim adds them (as a cause to another variable).
Models represented graphically can show the same variable in many different views; conversely a variable present in the model might not be displayed in any view. The variable can be shown as a regular variable (with causes attached), or a shadow variable (without causes attached).
NOTE It is possible to build separate working models in different views, but this is not recommended unless you intend to link them causally together at some later time. It is better to build complete new models (this gives them their own name and Time Bounds).
