System and method implementing function blocks for specifying and performing a signal analysis function utilizing multiple instruments, including two or more virtual instruments (VIs). Each function block includes: a function block icon for display in a graphical user interface (GUI) of a signal analysis function development environment, that visually indicates a respective signal operation; and associated program instructions executable to perform the respective operation. Each function block is selectable from the function blocks by a user for inclusion in a set of function blocks, each operable to perform their respective signal operation continuously upon selection, and to provide a respective output, operable to be displayed in the GUI, provided as input to other function blocks, and/or exported to an external device. The set of function blocks is executable to perform the signal analysis function under the signal analysis function development environment using one or more of the multiple instruments.