Leadership’s Role in Process Safety: An Understanding of Behavioral Science Among Managers and Executives Is Needed

ABSTRACT

A recent prevalence of high visibility catastrophic events has garnered increased attention to process safety issues. While the use of Behavior-Based Safety interventions demonstrate a reduction in workplace injuries by targeting employee behavior, we believe that process safety requires a greater focus on the behavior of leaders (e.g., creating and executing strategy). One effective method to begin targeting leader behavior for the improvement of process safety is to teach leaders about the principles of behavior, including ways by which the science may be applied within their own organizational models.     

基于σ/ Q 的库存控制中安全库存的优选策略

研究了单项目库存控制问题中的安全库存选择策略,评论了安全库存的决定要素,讨论 了基于以上要素的成本构成。进一步讨论了安全库存策略在理论和实践应用中的矛盾,提出 了一种实践中容易操作的安全库存的直观求解方法,以利于管理者实际运用,有效克服运作环 境的不确定性     

(Mis)understanding Safety Culture and Its Relationship to Safety Management

Although the concept of safety culture was coined in relation to major accidents like Chernobyl and Piper Alpha, it has been embraced by the safety community at large as a cause for unsafe practice. In this article, three approaches to safety culture are discussed in terms of their underlying concepts of culture and organizational culture. Culture is an intangible, fuzzy concept encompassing acquired assumptions that is shared among the members of a group and that provides meaning to their perceptions and actions and those of others. The basic assumptions that form the essence of a culture are shared, yet tacit, convictions, which manifest themselves subtly in the visible world. As applied by safety researchers, the culture concept is deprived of much of its depth and subtlety, and is morphed into a grab bag of behavioral and other visible characteristics, without reference to the meaning these characteristics might actually have, and often infused with normative overtones. By combining the three approaches, we can resurrect the notion of safety culture and strengthen its analytical potential in understanding the development and implementation of safety management systems.     

A Model for Setting Performance Objectives for Salmonella in the Broiler Supply Chain

A stochastic model for setting performance objectives for Salmonella in the broiler supply chain was developed. The goal of this study was to develop a model by which performance objectives for Salmonella prevalence at various points in the production chain can be determined, based on a preset final performance objective at the end of the processing line. The transmission of Salmonella through the broiler production chain was modeled. The prevalence at flock level was calculated from the measured prevalence at sample level. The transmission model is based on data on the occurrence of Salmonella collected in the Dutch broiler production chain during several years. The developed model can be used by policymakers and industry to determine economically and politically acceptable performance objectives for various points of the production chain and to draw conclusions about which interventions are most appropriate.     

Changes in Risk Perceptions Prospectively Predict Changes in Self‐Reported Speeding

Risk perception theories posit that changes in risk perception prompt subsequent changes in risk behavior. Prospective studies using observations made at three time‐points offer the capacity to test this hypothesis by observing sequential changes in both risk perceptions and behavior. A telephone survey was administered by random‐digit dialing to 255 adult Australian drivers at baseline (T1), 6 weeks (T2), and 14 weeks (T3). During weeks 2–5, a risk‐perception‐based anti‐speeding mass media campaign was conducted. The survey assessed risk perception, operationalized as the proportion of time that driving at 70 km/h (43 mph) was perceived to be dangerous, and self‐reported speeding behavior, defined as the frequency of respondents driving 5 km (3 mph) faster than the legal speed limit in built up areas. Higher T2 risk perception predicted lower T3 self‐reports of speeding after controlling T1 risk perception and T1 and T2 self‐reported speeding. This can be interpreted as changes in risk perceptions between T1 and T2 predicting changes in speeding between T2 and T3. Further analyses showed that increases in risk perception predicted lower subsequent self‐reported speeding changes, but decreases in risk perception were unrelated to those changes. Risk perception changes were unrelated to recall of exposure to the media campaign. These findings support a dynamic view of the relationship between risk perception and self‐reported behavior, and that risk perception theories can be applied to speeding.     

A New Methodology for Before–After Safety Assessment Using Survival Analysis and Longitudinal Data

The widely used empirical Bayes (EB) and full Bayes (FB) methods for before–after safety assessment are sometimes limited because of the extensive data needs from additional reference sites. To address this issue, this study proposes a novel before–after safety evaluation methodology based on survival analysis and longitudinal data as an alternative to the EB/FB method. A Bayesian survival analysis (SARE) model with a random effect term to address the unobserved heterogeneity across sites is developed. The proposed survival analysis method is validated through a simulation study before its application. Subsequently, the SARE model is developed in a case study to evaluate the safety effectiveness of a recent red‐light‐running photo enforcement program in New Jersey. As demonstrated in the simulation and the case study, the survival analysis can provide valid estimates using only data from treated sites, and thus its results will not be affected by the selection of defective or insufficient reference sites. In addition, the proposed approach can take into account the censored data generated due to the transition from the before period to the after period, which has not been previously explored in the literature. Using individual crashes as units of analysis, survival analysis can incorporate longitudinal covariates such as the traffic volume and weather variation, and thus can explicitly account for the potential temporal heterogeneity.     

Hazard Analysis and Safety Requirements for Small Drone Operations: To What Extent Do Popular Drones Embed Safety?

Currently, published risk analyses for drones refer mainly to commercial systems, use data from civil aviation, and are based on probabilistic approaches without suggesting an inclusive list of hazards and respective requirements. Within this context, this article presents: (1) a set of safety requirements generated from the application of the systems theoretic process analysis (STPA) technique on a generic small drone system; (2) a gap analysis between the set of safety requirements and the ones met by 19 popular drone models; (3) the extent of the differences between those models, their manufacturers, and the countries of origin; and (4) the association of drone prices with the extent they meet the requirements derived by STPA. The application of STPA resulted in 70 safety requirements distributed across the authority, manufacturer, end user, or drone automation levels. A gap analysis showed high dissimilarities regarding the extent to which the 19 drones meet the same safety requirements. Statistical results suggested a positive correlation between drone prices and the extent that the 19 drones studied herein met the safety requirements generated by STPA, and significant differences were identified among the manufacturers. This work complements the existing risk assessment frameworks for small drones, and contributes to the establishment of a commonly endorsed international risk analysis framework. Such a framework will support the development of a holistic and methodologically justified standardization scheme for small drone flights.     

Toward an Application Guide for Safety Integrity Level Allocation in Railway Systems

The work in the article presents the development of an application guide based on feedback and comments stemming from various railway actors on their practices of SIL allocation to railway safety‐related functions. The initial generic methodology for SIL allocation has been updated to be applied to railway rolling stock safety‐related functions in order to solve the SIL concept application issues. Various actors dealing with railway SIL allocation problems are the intended target of the methodology; its principles will be summarized in this article with a focus on modifications and precisions made in order to establish a practical guide for railway safety authorities. The methodology is based on the flowchart formalism used in CSM (common safety method) European regulation. It starts with the use of quantitative safety requirements, particularly tolerable hazard rates (THR). THR apportioning rules are applied. On the one hand, the rules are related to classical logical combinations of safety‐related functions preventing hazard occurrence. On the other hand, to take into account technical conditions (last safety weak link, functional dependencies, technological complexity, etc.), specific rules implicitly used in existing practices are defined for readjusting some THR values. SIL allocation process based on apportioned and validated THR values is finally illustrated through the example of “emergency brake” subsystems. Some specific SIL allocation rules are also defined and illustrated.     

Translating cross-lagged effects into incidence rates and risk ratios: The case of psychosocial safety climate and depression

Longitudinal studies are the gold standard of empirical work and stress research whenever experiments are not plausible. Frequently, scales are used to assess risk factors and their consequences, and cross-lagged effects are estimated to determine possible risks. Methods to translate cross-lagged effects into risk ratios to facilitate risk assessment do not yet exist, which creates a divide between psychological and epidemiological work stress research. The aim of the present paper is to demonstrate how cross-lagged effects can be used to assess the risk ratio of different levels of psychosocial safety climate (PSC) in organisations, an important psychosocial risk for the development of depression. We used available longitudinal evidence from the Australian Workplace Barometer (N?=?1905) to estimate cross-lagged effects of PSC on depression. We applied continuous time modelling to obtain time-scalable cross effects. These were further investigated in a 4-year Monte Carlo simulation, which translated them into 4-year incident rates. Incident rates were determined by relying on clinically relevant 2-year periods of depression. We suggest a critical value of PSC?=?26 (corresponding to ?1.4 SD), which is indicative of more than 100% increased incidents of persistent depressive disorder in 4-year periods compared to average levels of PSC across 4 years.     

Risk, Trust, and Safety Culture in U.K. Train Operating Companies

Organizational safety culture reflects the attitudes and behaviors that individuals share in considering and reacting to hazards and risks. We first argue that trust is an underdeveloped and important concept in relation to theories of safety culture and high-reliability organizations. The article then reports findings from a two-year qualitative study of train operating companies (TOCs) in the United Kingdom, which sought to explore in detail the linkages between safety culture and the postprivatized railway industry. In-depth interviews and focus groups were carried out with a sample of over 500 employees, from four organizations, and representing all key functional levels. Our analysis suggests that the 1993 privatization, and subsequent organizational restructuring of the U.K. railway industry, has had important repercussions for both safety culture and trust relationships. We explore our findings in relation to three key constructs within "safe organizations" theories (namely, flexibility, commitment, and learning), and discuss how the safe organization model might be usefully supplemented by a consideration of trust issues.