The Flow Sheet Window gives a graphical depiction of the data processing flow through the various SU modules. Pull-down menus are available for adding modules to the canvas via the Module List Window, deleting or inactivating modules, viewing a selected module's Parameter List Window, and accessing online help. Input/output ports are color-coded for ease of matching compatible formats. Modules and their connecting pipes may be moved around on the canvas. Each saved flow sheet creates a shell script which can be run through the SU processing package in real time or in background mode.