The article considers a single-machine n-job scheduling problem to minimize the sum of absolute lateness given a common due date. Two models are defined depending on whether the start time t0 of schedules is arbitrary or fixed. Conditions are provided when those two models coincide. The developed branch-and-bound procedure is tested on nine known examples from the literature (6•n•14) and 90 medium-size random problems (15•n•25) with a fixed t0.
