Designing safe job rotation schedules using optimization and heuristic search

Abstract

Job rotation is one method that is sometimes used to reduce exposure to strenuous materials handling; however, developing effective rotation schedules can be complex in even moderate sized facilities. The purpose of this research is to develop methods of incorporating safety criteria into scheduling algorithms to produce job rotation schedules that reduce the potential for injury. Integer programming and a genetic algorithm were used to construct job rotation schedules. Schedules were comprised of lifting tasks whose potential for causing injury was assessed with the Job Severity Index. Each method was used to design four job rotation schedules that met specified safety criteria in a working environment where the object weight, horizontal distance and repetition rate varied over time. Each rotation was assigned to a specific gender/lifting capacity group. Five versions of the integer programming search method were applied to this problem. Each version generated one job rotation schedule. The genetic algorithm model was able to create a population of 437 feasible solutions to the rotation problem. Utilizing cluster analysis, a rule set was derived from the genetic algorithm generated solutions. These rules provided guidelines for designing safe job rotation schedules without the use of a computer. The advantages and limitations of these approaches in developing administrative controls for the prevention of back injury are discussed.

A genetic algorithm for the design of job rotation schedules considering ergonomic and competence criteria

“…In previous works, this problem was solved using integer programming [6,[12][13][14][15][16], heuristics [17], metaheuristics such as genetic algorithms [6,12,15,[18][19][20], simulated annealing [15,21] or ant algorithms [22] or by combining integer programming and metaheuristic models [6,15]. In these studies, rotation schedules were developed for different purposes.…”

A method to design job rotation schedules to prevent work-related musculoskeletal disorders in repetitive work

“…For example, Carnahan et al (2000) develop a genetic algorithm to design schedules of rotation jobs to prevent back injuries. Carnahan´s algorithm calculates the risk level for lifting tasks in each workstation by means of the Job Severity Index ergonomic method (Liles, 1986).…”

An investigation of production workers’ performance variations and the potential impact of attitudes

“…Second, designers do not appreciate the stochastic nature of human/social dynamics within manufacturing systems and how this increases system complexity (Mollaghasemi et al, 1998;Azadeh, 2000;Baines and Ladbrook, 2002;Pacquet and Lin, 2003). Third, system designers assume that human variability in the performance of production is too constrained and regulated by automated/mechanical functions and job simplification to exceed the standardisations derived from time study techniques for line balancing (Carnahan et al, 2000).…”