FMEA and Fault Tree Ananlysis Applied to Vendor Customer Technical Bulletins
B Miller1*, B Movsas2, M Siddiqui2, T Nurushev2, I Chetty2, (1) Henry Ford Health System, Clinton Township, MI (2) Henry Ford Health System, Detroit, MIWE-E-141-9 Wednesday 2:00PM - 3:50PM Room: 141
Purpose:Over the past 3 years our institution has received 44 Customer Technical Bulletins (CTBs) from vendors that supply us with hardware of software used for patient care. We have ranked the failure modes presented to our institution in these CTBs using Failure Mode and Effects Analysis (FMEA) tools as described in the AAPM report TG-100.
Methods:FMEA applied to the failure modes comes up with a Risk Probability Number based on the severity, probability of occurrence and probability it will go undetected. In addition to FMEA, the adverse effects on our patient population are examined by looking at the number of people affected. For example, CTBs applying to dose calculations would affect 100% of our patients while CTBs applying to IMRT calculations will affect approximately 50% or our patient population.
Results:Of the 44 CTBs received from vendors we identified nineteen with Risk Priority Numbers (RPN) greater than 200 and four of those had RPN greater than 300. Of the four with RPN greater than 300, two dealt with incorrect dose calculations due to incorrect commissioning of the treatment planning system, one with the CT datasets getting flipped and the last with isocenter being transferred incorrectly. Each of these failure pathways would have resulted in a systematic error that would have affected a large population of patients. For the failure modes with RPN greater than 200 the average RPN was reduced from 275 to 70 after modifying policy, checklists and improving clinical flow.
Conclusion:Analysis of vendor CTBs and review by a departments QA committee is an essential part of any QA program. By applying FMEA and analyzing the fault trees discussed in these bulletins, we were able to reduce the RPN from an average of 275 to 70.