Framework for permit to work assessment

Abstract

Permit to work (PTW) is an official document used as a means of communication, control, and managing work activities to prevent accidents at petrochemical plants. However, there are cases whereby the PTW has failed to control work activities resulting in occupational accidents. Hence, this study was conducted to develop a framework for permit to work assessment related to occupational accidents in petrochemical plants. For this assessment, the PTW and occupational accidents questionnaires were verified by expert panels according to Delphi technique for five (5) selective PTW elements, i.e. hazardous activity, worksite inspection, supporting document, work description, and closeout. A total of 260 survey questionnaires were distributed to work leaders and workers at the selected plants. The data were analyzed using the exploratory factor analysis and confirmatory factor analysis methods. Next, a structural equation model (SEM) was employed to identify the most significant element(s) related to the failure of PTW. The assessment results revealed that hazardous activity was the leading cause of occupational accidents in petrochemical plants. The SEM results were validated using the fault tree analysis technique, which indicated that the same rank of factors contributed to the occupational accident. In addition, a simple multilinear regression of the PTW element was used to develop predictive modelling, which was validated using a case study. Finally, the framework for permit to work assessment of occupational accidents in petrochemical plant has been developed. This framework can be further developed to extend the PTW assessment of occupational accident from other types of industry.