Productivity of Multiprogrammed Computers-Progress
in Developing an Analytic Prediction Method
Multiprogramming as it is discussed here is
a mode of computer operation in which two or more
programs are concurrently in processor memory and proceeding,
each using the same central processor unit 
(CPU) and input-output (I/O) channels.  These programs
are actually proceeding intermittently and singly, 
according to eligibility (readiness to proceed) and priority.
 It is useful to be able to represent them 
as proceeding continuously and simultaneously, each
at an effective rate, which may be a fraction of 
that which it would enjoy in the absence of the other
programs.  The effective progress rate of each 
program is sensitive to many detailed characteristics
of itself and its co-residents and simulation has 
been the best available method of predicting it.  This
paper presents the results of progress in developing 
an alternative to simulation, a simulation-tested iterative
computation of these rates under certain 
situations.  The algorithm is sensitive to most of the
factors that control the phenomenon, including 
nonquantitative or topological features of the programs' structures.
CACM December, 1969
Lasser, D. J.
