Aversion scheduling in the presence of risky jobs

Empirical studies have shown that human schedulers use special procedures to deal with troublesome jobs that are perceived to disrupt manufacturing or that will take substantially longer than the industrial engineering standards. These troublesome jobs present a risk to the manufacturing process and to the schedule robustness. One strategy is to delay them whenever possible and to allow other work to overtake. The Aversion Dynamics concept is used to include this type of logic in scheduling heuristics such that a trade-off analysis of penalties occurs in light of the expected performance results. This is accomplished by altering processing time estimates to achieve a form of ‘safety time’ for risky jobs. This paper conducts a large empirical study within the single-machine static arrival environment to demonstrate that the concept of special sequencing based on job risk is significant and that robust strategies can be developed.