Quality and speed trade-offs in manufacturing systems

A methodology for modeling quality-speed tradeoffs in manufacturing systems is discussed. This is done by approximating the quality characteristic achieved as normally distributed with the standard deviation of the process being a convex increasing function with respect to speed. For a single-stage system, it is shown that the profit rate function is quasi-concave and there is a unique maximum. The optimum speed obtained by maximizing profit rate is shown to be greater than the optimum minimum cost speed. A numerical example is presented