OCI Nitrogen wants to gain knowledge of (leading) indicators regarding the process safety performance of their ammonia production process. This paper answers the question whether indicators can be derived from the barrier system status to provide information about the development and likelihood of the major accident processes in the ammonia production process. The accident processes are visualized as scenarios in bowties. This research focuses on the status of the preventive barriers on the left-hand side of the bowtie. Both the quality – expressed in reliability/availability and effectiveness – and the activation of the barrier system give an indication of the development of the accident scenarios and the likelihood of the central event. This likelihood is calculated as a loss of risk reduction compared to the original design. The calculation results in an indicator called “preventive barrier indicator”, which should initiate further action. Based on an example, it is demonstrated which actions should be taken and what their urgency is.

There has been an increase in research into the security culture in organizations in recent years. This growing interest has been accompanied by the development of tools to measure the level of security culture in order to identify potential threats and formulate solutions. This article provides a systematic overview of the existing tools. A total of 16 are identified, of which six are studied in detail. This exploration reveals that there is no validated and widely accepted tool that can be used in different sectors and organizations. The majority of the tools reviewed use only a quantitative method; however, security culture includes very different domains and therefore a mixed-method approach should be used. In contrast to security culture, instruments for measuring safety culture are widely available, and with many similarities between these two domains it is possible that well-established tools for measuring safety culture could be adapted to a security environment.