Precedence constrained scheduling in $(2-\frac{7}{3p+1})\cdot$optimal

Abstract

We present a polynomial time approximation algorithm for unit time precedence constrained scheduling. Our algorithm guarantees schedules which are at most $(2-\frac{7}{3p+1})$ factor as long as the optimal, where $p>3$ is the number of processors. This improves upon a long standing bound of $(2-\frac{2}{p})$ due to Coffman and Graham.