Designing an improved work shift system for the nightshift workers of Simon Enterprises, Inc.

Date of Publication


Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Industrial Engineering

Subject Categories



Gokongwei College of Engineering


Industrial Engineering


Awarded as best thesis, 1999


Abstract. Initial findings of the study yielded similar results as that of previous studies and experiments conducted concerning the difference in productivity rates between night shift and morning shift workers. The study further revealed that the subjective feelings of fatigue such as yawning, drowsiness, and excessive blinking of eyes had contributed to the decrease in the night shift's productivity rate. Thus, the group found a renewed interest to continue on with the study.

The main concern of the study was to design an improved work shift system for the night shift workers of Simon Enterprises, Inc., which is engaged in importation and distribution of animal feeds. The objective of this study was to increase the present level of productivity to the same level as that of the morning shift or higher. Correspondingly, it also aimed to find ways to reduce the subjective feelings of fatigue that occur more often during the nightshift by 10%.

The group applied the statistical tool, Design of Experiment (DOE), in conducting the series of experiments for the factors. Several factors that were considered to have a great impact on the nightshift workers were experimented and validated. These factors were lighting, schedule of breaktime, schedule of shift rotation, music and naptime. The data gathered from the experiments were then input to the software, Design-Expert (D x 5), to generate analytical computations and graphical representations. To carry on, the group made the necessary analyses and interpretations of the results.

Consequently, the results obtained led the group to decide on the proposed setting. The proposed setting embodied the optimal levels of the different significant factors of the study. First, illumination level should be increased to improve alertness of the nightshift workers. Second, the schedule of breaktime is recommended to be set at 2:50 where the core body temperature would be at its critical. Lastly, shift rotation schedule should be shortened to lessen the buildup of sleep debt in a row. With the given proposed setting, the study was able to meet the objectives of the study.

The solutions only embodied the environmental factors of the shift system since medical and other physiological issues were not under the scope of the study.

Abstract Format






Accession Number


Shelf Location

Archives, The Learning Commons, 12F Henry Sy Sr. Hall

Physical Description

97 leaves

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