1. A method for execution on a digital computer for optimizing the instruction path length in the compilation of COBOL source code, said source code including PERFORM statements and preselected procedures associated therewith, an improvement comprising the steps of: (a) ascertaining the control transfer relationship among PERFORM statements and their associated procedures, and characterizing said ascertained relationship in a vector of attributes for each PERFORM statement including whether an associated procedure is OPEN or CLOSED; and (b) interpreting the vectors such that if the vector for any given PERFORM statement indicates that: (1) the procedure associated therewith is CLOSED, then the code constituting the procedure is substituted for the code constituting the PERFORM statement, or (2) the procedure associated therewith is OPEN, then a simplified transfer and return of control code is substituted for the original code constituting the transfer and return of control.