Systems Theoretic Accident Model and Process application : quality control in medical device manufacturing

Abstract

The goal of medical device industry is to provide patients and healthcare professionals effective, reliable, safe and affordable products. However, due to the dynamic and competitive operation and business environment, most manufacturers did not always attain this goal. It is a challenge to balance the demands of meeting government regulations and containing production costs, in an effort to produce the most effective, reliable and safest medical devices. The increasing complexity on product structures, production process and usage context make this task even more formidable. The increase in serious adverse events has outpaced industry growth by 8 % since 2001[1], which reflects the insufficiency of traditional quality control measures. The disastrous consequences of quality hazards usually have profound impact on customers, manufacturers, and communities. Therefore, it is imperative to look for a better way to achieve effective quality control in medical device industry. The purpose of the thesis is to compare the traditional quality control measures, which are now widely adopted in quality systems of medical device industry for designing and development, process control and non-conformance handling, with the approach of Systems Theoretic Accident Model and Process (STAMP) based System-Theoretic Process Analysis (STPA) method. Through the case study on real quality issue in manufacturing control, this work analyzes the current states of complex manufacturing process controls that are designed by utilizing traditional principles and tools, and demonstrates the improvement after the STPA techniques was applied to the same cases. The advantages of STPA technique is to model the process to system control structure without oversimplifying any possible influencing factors, and then examine the links an interaction among these factors to reveal what constraints need to be installed and are followed to ensure that the system performs in safe zone and deliver the expected outcomes. This approach can effectively reveal hidden defects and dangers in system that the traditional measures are not able to detect, and thus is very helpful to the high-stake industry such as medical device manufacturing to prevent potential serious adverse events and protect patients from injuries caused by accidents of quality hazards.