WIT Press

Emerging tools for evaluating safety management systems effectiveness


Free (open access)


Volume 6 (2016), Issue 2



Page Range

310 - 320

Paper DOI



WIT Press




Safety Management Systems (SMS) have become prevalent in a host of industries, including aviation, for managing safety, but little research has been performed to-date on measuring the effectiveness of SMS. This research examined the independent application of two related concepts to assess effective- ness: IO/SMS, an Input-Output economics concept applied to SMS, and Data Envelopment Analysis (DEA). Input-Output (IO) is a method for systematically determining the inter-relationships among ele- ments in a system. To determine if IO could be applied to SMS, it was necessary to calculate the relative importance to the system of the four components of SMS. Five SMS experts participated and, through a series of exercises, determined values for the 24 discrete SMS parts. Using IO matrix math, these values were then calculated for a 24×24 matrix. The results produced a matrix that could be used to predict the impact on the system by changing either a total input value such as an aggregate score on a survey, or by changing a single value. DEA is a multi-factor, mathematical programming technique that is used to determine the boundary of an efficient frontier. Using inputs and outputs, a ratio is calculated, which measures the relative efficiency, or effectiveness, of each decision making unit (DMU). In this research, inputs and outputs were determined for each of the four components of SMS via surveys conducted by subject matter experts. DEA models were developed and tested, and efficiency scores were developed for each DMU. DEA modeling also revealed the specific areas that could be addressed to improve efficiency scores. IO/SMS and DEA appear to be powerful tools to measure SMS effectiveness. A next step in the research may be to examine techniques that combine the benefits of both methods.


data envelopment analysis, emerging tools, input-output analysis, safety management systems