Applying Mathematical Modeling to Create Job Rotation Schedules for Minimizing Occupational Noise Exposure

Abstract

This research developed worker schedules by using administrative controls and a computer programming model to reduce the likelihood of worker hearing loss. By rotating the workers through different jobs during the day it was possible to reduce their exposure to hazardous noise levels. Computer simulations were made based on data collected in a real setting. Worker schedules currently used at the site are compared with proposed worker schedules from the computer simulations. For the worker assignment plans found by the computer model, the authors calculate a significant decrease in time-weighted average (TWA) sound level exposure. The maximum daily dose that any worker is exposed to is reduced by 58.8%, and the maximum TWA value for the workers is reduced by 3.8 dB from the current schedule.

A multi-criteria genetic algorithm for the generation of job rotation schedules

“…It is therefore recommended that the job planner uses tools that enable him to create and evaluate rotations quickly and flexibly, taking into account all the aspects that impinge on correct job assignation and the restrictions that assure the viability of the results obtained. Although various approaches to the problem of job rotation have been studied (Carnahan et al, 2000;Tharmmaphornphilas et al, 2003), this paper sets about the subject by proposing a genetic algorithm, which considers the conditions that maximize benefits from job rotation. In the process of generation of assignation alternatives the proposed algorithm considers that: the muscle groups involved in the various jobs performed by the worker in the different rotations should not be the same, the content of the jobs to be performed should involve an effective change of activity, and the preferences of the workers for certain jobs should be taken into account.…”

Taxonomy for integrating scheduling theory and human factors: Review and research opportunities

“…Other examples include reducing cumulative trauma disorders (Triggs and King, 2000), minimizing occupational noise exposure (Tharmmaphornphilas et al, 2003), and reducing the risk of lower back pain (Frazer et al, 2003). The nature of the empirical research is to examine the effectiveness of job rotation and is not concerned with determining the best job rotation schedules.…”

“…Carnahan et al (2001) applied genetic algorithms to an assembly line balancing problem to minimize cycle time and worker fatigue, where fatigue is measured as the percentage grip strength after 4 h of work. Tharmmaphornphilas et al (2003) developed an integer programming formulation for rotating workers among jobs to minimize occupational noise exposure in a sawmill. Eleven workers were rotated among 11 jobs through four work periods, and the number of possible schedules was (11!)…”

A model used in creating a work-rest schedule for laborers

“…The proper design of a work-rest schedule may be effective in improving a worker's comfort, health, and productivity [19,20]. Tharmmaphornphilas et al [7] proposed a mathematical model to create job rotation schedules to minimize the noise exposure for laborers working in a sawmill. A reduction of 58.8% in maximum daily dose was reported by them and 3.8 dB of maximum time-weighted average sound level can be achieved by optimizing the work schedule.…”

“…Possible preventive measures such as proper organization of work can be used to avoid physical fatigue in workers [6]. Proper job rotation has been advocated as an administrative control in order to improve the organization of the work [7][8][9][10][11][12][13][14].…”