A note on Syms' benchmarked comparison
Paul L. Lujanac · ACM SIGMETRICS Performance Evaluation Review · 1974
If the load factor is expressed linearly as a fraction of the capacity of a terminal-oriented system, we assume that response times increase more or less exponentially with an increase in load factor. Syms' load factor is nonlinear, and, in fact, was designed to "make the terminal response times approximately a linear function of the load factors."