A method for programming a computer to execute a procedure is based on a graphical interface which utilizes data flow diagrams to represent the procedure. The method stores a plurality of executable functions, scheduling functions, and data types. A data flow diagram is assembled in response to the user input utilizing icons which correspond to the respective executable functions, scheduling functions, and data types which are interconnected by arcs on the screen. A panel, representative of an instrument fron panel having input and output formats is likewise assembled for the data flow diagram. An executable program is generated in response to the data flow diagram and the panel utilizing the executable functions, scheduling functions, and data types stored in the memory. Furthermore, the executable functions may include user defined functions that have been generated using the method for programming. In this manner, a hierarchy of procedures is implemented, each represented by a data flow diagram.