Lawler's algorithm

Lawler’s algorithm is a powerful technique for solving a verity of constrained scheduling problems. The algorithm handles any precedence constraints. It schedules a set of simultaneously arriving tasks on one processor with precedence constraints to minimize maximum tardiness or lateness. Precedence constraints occur when certain jobs must be completed before other jobs can be started.

Objective Functions

The objective function is assumed to be in the form $min\,max_{0\leq i\leq n}\,g_{i}(F_{i})$, where $g_{i}$ is any nondecreasing function and $F_{i}$ is the flow time. When $g_{i}(F_{i})=F_{i}-d_{i}=L_{i}$, the objective function corresponds to minimizing the maximum lateness, where $d_{i}$ is due time for job $i$ and $L_{i}$ lateness of job $i$. Another expression is $g_{i}(F_{i})=max{(F_{i}-d_{i},0)}$, which corresponds to minimizing the maximum tardiness.

Additional readings

• Michael Pinedo. Scheduling: theory, algorithms, and systems. 2008. ISBN 9780387789347
• Conway, Maxwell, Miller. Theory of Scheduling. 1967. ISBN 0486428176