I'm rather new to Model Builder. I'm trying to build a model that solves a Service Area through Network Analyst. I want to export the polygons generated into their own feature class / shapefile. I can do this, but only after running all steps prior to the export. That is, I must first generate the derived Service Area layer prior to exporting it. Without first running the Solve, I cannot export my Service Area polygons because they don't yet exist.
How can I build a model that knows to expect a derived Service Area polygon layer that will be converted into a feature class upon which the rest of the model can proceed?
Use the Select Data tool as described in the help topic Using the Select Data tool There's an example model at the bottom of the page that shows using it with Make Route Layer -- your model will be very similar.