There are two ways to set a precondition for a tool:
- From Tool Properties
- Using the Connect tool
Setting Precondition From Tool Properties
- Right-click a tool element and select Properties.
- In the Properties window, click the Precondition tab and check the variable for which you want to make a precondition to the tool.
Setting Precondition Using the Connect tool
- In the model, use the Connect button to connect a variable to a tool element.
- Choose Precondition from the list of available parameters. When the model is run either from within ModelBuilder or from the model tool dialog box, the tool element with the precondition will not execute until the variable has a valid value.