A Controlled Experiment Investigating the Effects of Explanatory Manual on Adherence to Operating Procedures

Operators’ adherence to operating procedures is a crucial factor for process safety in the process industry. Instruction manuals that document Standard Operating Procedures (SOP) are commonly used both as training materials and references during operation. Traditional SOP manual design emphasized using simple step-by-step instructions for how to do the tasks, but it often neglected the reasons why the steps and their specific orders should be closely followed. It is evident that operators sometimes choose to deviate from SOP intentionally if they do not understand the reasons and incorrectly deem the steps in the manual as slow or outdated. To help bridge the knowledge gap between SOP designers and operators, we advocate explanatory SOP manual design that adds the reasons for the steps in manual instructions. To examine the effect of explanatory manual, we conducted a controlled experiment using a hydraulic pump system that represented the wash operation in the electroplating industry. Participants’ performance and adherence to operating procedures (both Adherence to Production Order Procedures and Adherence to Wait Time) were measured and compared between the explanatory manual and the procedural manual conditions. The results showed that the explanatory manual had the benefit of increasing Adherence to Production Order Procedures, while time performance, Percent Duration within Bounds, and Adherence to Wait Time were not significantly affected. The finding supports the use of explanatory manuals because they have the potential to serve as an effective and economic way to improve operators’ adherence to operating procedures and process safety. Limitations of the laboratory setup were discussed