Source : Free On-Line Dictionary of Computing

Delivered Source Instruction
     
         (DSI) One line of source code (LOC)
        developed by a project.
     
        DSI is the primary input to many tools for estimating software
        cost.  The term "delivered" is generally meant to exclude
        non-delivered support software such as test drivers.  However,
        if these are developed with the same care as delivered
        software, with their own reviews, test plans, documentation,
        etc., then they should be counted.  The "source instructions"
        include all program instructions created by project personnel
        and processed into {machine code} by some combination of
        preprocessors, compilers, and assemblers.  It excludes
        comments and unmodified utility software.  It includes {job
        control language}, format statements, and data declarations.
     
        (1996-05-29)