The model that you work with throughout this tutorial is a simple manifold block. The block contains a set of three available ports referenced as A, B, and C. Each port is on a different side of the block. A port consists of a center hole (of variable size), and a set of surrounding threaded bolt holes. The holes are used to mount union caps in a later tutorial.
This manifold block can be either a tee style block, which has all three ports, or an elbow style block with only two ports. Also, the block can be either a standard block or a custom block. On a standard block, which can be ordered off the shelf, all ports are the same size. A custom block, which must be manufactured, can feature a different size for each port.
Finally, the part contains an embedded Microsoft Excel spreadsheet, which is used to specify the values for various parameters as the port sizes are changed.
You begin by adding additional parameters to the model to support the rules you write later.