A note on the SPT heuristic for solving scheduling problems with generalized due dates

Two NP-hard scheduling problems on parallel identical machines with generalized due dates are studied. We focus on two objectives: (i) minimizing maximum tardiness and (ii) minimizing total tardiness. In both cases, we introduce a shortest processing time first (SPT)-based heuristic and simple lower bounds on the optimal cost. Our numerical study indicates that the SPT heuristic performs extremely well in all settings.