Working with ModelBuilder

ModelBuilder is the graphical environment in which you create and interact with models. The building block of a model is called a process. A process consists of a geoprocessing tool.

Every tool has parameters, including an input dataset, values that tell the tool what to do (such as the distance value for the buffer tool), and an output dataset. When displayed graphically in a model, the individual parts of a process are called elements.

A process consists of a geoprocessing tool. A tool requires an input dataset and produces an output dataset using specified parameters.

In ModelBuilder, a model is represented by a diagram that shows all the processes and the sequence in which they run. The connecting arrows show how elements and processes are related to each other.

In a model, processes are connected by arrows. This model contains two processes: buffer and clip.

A model reflects a geoprocessing workflow—the output of one process is used as the input for another. Models can mirror simple geoprocessing workflows, like the example above, or a complicated workflow, like the one below.

Models can contain as many processes as you need to accomplish your geoprocessing work.

To add a process to a model, simply find the appropriate tool in ArcToolbox or ArcCatalog and drag it into the model. Any of the ArcGIS geoprocessing tools can be used in a model. You can also drag and drop data into a model from ArcCatalog or ArcMap.

In a model, the way elements are symbolized tells you something. White elements are not ready to run—most likely, a tool parameter needs to be entered. If all the elements in a process are colored, this means the tool has everything it needs and the process is ready to run. When tools and outputs display with a dropshadow, that means the process has run successfully.

Model elements can be in one of three states: white elements are not ready to run, colored elements are ready to run, and elements with a dropshadow have finished running.

You can work with an existing model or you can build your own. As you will see in the next exercise, building a model is a straightforward process.