Dynamics of safety performance and culture: A group model building approach

The management of occupational health and safety (OHS) including safety culture interventions is comprised of complex problems that are often hard to scope and define. Due to the dynamic nature and complexity of OHS management, the concept of system dynamics (SD) is used to analyze accident prevention. In this paper, a system dynamics group model building (GMB) approach is used to create a causal loop diagram of the underlying factors influencing the OHS performance of a major drilling and mining contractor in Australia. While the organization has invested considerable resources into OHS their disabling injury frequency rate (DIFR) has not been decreasing. With this in mind, rich individualistic knowledge about the dynamics influencing the DIFR was acquired from experienced employees with operations, health and safety and training background using a GMB workshop. Findings derived from the workshop were used to develop a series of causal loop diagrams that includes a wide range of dynamics that can assist in better understanding the causal influences OHS performance. The causal loop diagram provides a tool for organizations to hypothesize the dynamics influencing effectiveness of OHS management, particularly the impact on DIFR. In addition the paper demonstrates that the SD GMB approach has significant potential in understanding and improving OHS management.     

From waste to value – a system dynamics model for strategic decision-making in closed-loop supply chains

Although the field of closed-loop supply chain management has attracted a lot of attention in recent years and the management of reverse logistics processes has become a major field of supply chain management, there is still a lack of research conducting analyses using a comprehensive approach that takes the complexity of problems of reverse logistics processes into account. Hence, the purpose of this paper is to develop a model that allows an original equipment manufacturer in the electronics industry to test different value recovery strategies for business-to-business products in a closed-loop supply chain setting. For this purpose system dynamics is used because this approach enables one to capture the high complexity of reverse logistics processes and is suitable, contrary to traditional optimisation approaches, for analysing the dynamic behaviour of closed-loop supply chains comprehensively. The simulation analysis identifies leverage points for the improvement of decisions concerning reverse logistics. In particular, the simulation runs conducted highlight the high complexity and connectivity inherited with various value recovery processes. The paper contributes to a better understanding of supply chain dynamics, the impact of product backflow, and reverse logistics.     

Behavior-based safety on construction sites: A case study

This work presents the results of a case study and describes an important area within the field of construction safety management, namely behavior-based safety (BBS). This paper adopts and develops a management approach for safety improvements in construction site environments. A rigorous behavioral safety system and its intervention program was implemented and deployed on target construction sites. After taking a few weeks of safety behavior measurements, the project management team implemented the designed intervention and measurements were taken. Goal-setting sessions were arranged on-site with workers’ participation to set realistic and attainable targets of performance. Safety performance measurements continued and the levels of performance and the targets were presented on feedback charts. Supervisors were asked to give workers recognition and praise when they acted safely or improved critical behaviors. Observers were requested to have discussions with workers, visit the site, distribute training materials to workers, and provide feedback to crews and display charts. They were required to talk to operatives in the presence of line managers. It was necessary to develop awareness and understanding of what was being measured. In the process, operatives learned how to act safely when conducting site tasks using the designed checklists. Current weekly scores were discussed in the weekly safety meetings and other operational site meetings with emphasis on how to achieve set targets. The reliability of the safety performance measures taken by the company's observers was monitored. A clear increase in safety performance level was achieved across all categories: personal protective equipment; housekeeping; access to heights; plant and equipment, and scaffolding. The research reveals that scores of safety performance at one project improved from 86% (at the end of 3rd week) to 92.9% during the 9th week. The results of intervention demonstrated large decreases in unsafe behaviors and significant increases in safe behaviors. The results of this case study showed that an approach based on goal setting, feedback, and an effective measure of safety behavior if properly applied by committed management, can improve safety performance significantly in construction site environments. The results proved that the BBS management technique can be applied to any country's culture, showing that it would be a good approach for improving the safety of front-line workers and that it has industry wide application for ongoing construction projects.     

Designer portfolio archetypes in design-intensive industries

ABSTRACT

The paper analyzes the designer portfolio configurations employed by firms, in design-intensive industries, to implement different product design strategies. Using the fuzzy set qualitative comparative analysis methodology, the paper explores how decorative lamps manufacturers, that first adopted the new LED technology, assembled their designer portfolios. The study shows that, in the early phases of LED lamps, four different designer portfolio archetypes were adopted by firms, two of them related to a product language divergence strategy and two to a product language convergence strategy: international design-star archetype, crowd design-innovator archetype, local ambassador archetype, international bridge archetype. These four archetypes are discussed, contributing to a better understanding of the relationship between product design strategies and designers’ management in design-intensive industries.     

System dynamics analytical modeling approach for construction project management research: A critical review and future directions

Building and infrastructure construction projects can be viewed as a complex system consisting of many subsystems. Over the last two decades, considerable researches that use system dynamics (SD) as an analytical and modeling approach exist to address construction project management issues. However, only few critical reviews have been conducted to provide an in-depth understanding of SD application in construction project management. Moreover, many studies have failed to apply SD accurately. Therefore, the present study aims to gain an understanding of the current state of play and future directions in applying SD method in construction project management research, by undertaking a comprehensive review of 105 relevant articles published from 1994 to 2018. These articles are analyzed in terms of annual publication rate, key papers and their contribution, critical issues in SD application, and research topics. A significant increase in the number of publications in the last five years has been observed. When applying SD method to model construction system, the following aspects must be carefully considered: Model boundary, model development, model test, and model simulation. In addition, SD has been applied in a wide range of research topics, including (1) sustainable construction; (2) design error, rework, and change management; (3) risk management; (4) resource management; (5) decision making; (6) hybrid modeling; (7) safety management; (8) PPP project; and (9) organization performance. Based on the review findings, this study discusses three future research directions, namely, integration of SD with other methods, uncertainty analysis, and human factor analysis. This study can help researchers gain an in-depth understanding of the critical issues in the application of SD in construction management and the state-of-the-art of SD research.     

An aggregation method of Markov graphs for the reliability analysis of hybrid systems

To meet always increasing safety requirements in car industry, design and safety assessment methods are developed in order to fit the complexity of new embedded mecatronic systems. Hybrid (discrete/continuous) and dynamic features, specific to these systems, require choosing a suitable formalism. These features should also be considered in safety studies made all through the system design. The aim of this paper is to propose a quantitative analysis method based on the construction of an aggregated Markov graph, which allows a limitation of the combinatorial expansion. This graph is directly deducted from the Petri net modelling of the system. It is composed by a set of functional modes and a set of transitions to which statistical information regarding the system dynamics has been added.     

An aggregation method of Markov graphs for the reliability analysis of hybrid systems

To meet always increasing safety requirements in car industry, design and safety assessment methods are developed in order to fit the complexity of new embedded mecatronic systems. Hybrid (discrete/continuous) and dynamic features, specific to these systems, require choosing a suitable formalism. These features should also be considered in safety studies made all through the system design. The aim of this paper is to propose a quantitative analysis method based on the construction of an aggregated Markov graph, which allows a limitation of the combinatorial expansion. This graph is directly deducted from the Petri net modelling of the system. It is composed by a set of functional modes and a set of transitions to which statistical information regarding the system dynamics has been added.     

Risk warning technologies and emergency response mechanisms in Sichuan–Tibet Railway construction

Safety is one of the most critical themes in any large-scale railway construction project. Recognizing the importance of safety in railway engineering, practitioners and researchers have proposed various standards and procedures to ensure safety in construction activities. In this study, we first review four critical research areas of risk warning technologies and emergency response mechanisms in railway construction, namely, (i) risk identification methods of large-scale railway construction projects, (ii) risk management of large-scale railway construction, (iii) emergency response planning and management, and (iv) emergency response and rescue mechanisms. After reviewing the existing studies, we present four corresponding research areas and recommendations on the Sichuan–Tibet Railway construction. This study aims to inject new significant theoretical elements into the decision-making process and construction of this railway project in China.     

Complexity analysis of manufacturing service ecosystem: a mapping-based computational experiment approach

The trend of servitisation is increasingly affecting manufacturing enterprises. Traditional manufacturing enterprises cannot handle the related challenges of service innovation by themselves. Recently, manufacturing service ecosystem (MSE) has been proposed to support service innovation by facilitating collaboration. The construction and development of MSE need to handle a series of complexities, such as individual complexity, interaction complexity and ecological complexity. However, it is still very difficult to clearly identify the possible effect of various influence factors on MSE evolution, which is necessary analyse the complex dynamic interactive relationship among participants, so as to maintain the sustainable and healthy development of MSE. To change such a situation, this paper proposes a mapping-based computational experiment approach to analyse the evolution of MSE. This approach has three main parts, i.e. model construction of real world, model mapping of computational system and experiment evaluation of various factors of MSE evolution. By adopting the proposed approach, several case studies are conducted to investigate the possible effect of cooperation preference on the MSE evolution in various market environments. The results demonstrate that the proposed approach is effective.     

危险化学品安全管控与应急救援

危险是危险化学品的天然特征,安全是危险化学品永恒的主题。每一次危险化学品的安全事故,既是其本质特征使然,也与外部环境密切相关,往往在其偶发性中包含着必然性。只有在充分了解、掌握其本质特征基础上,合理设置外部条件,使其始终处于可控的安全状态,并做好安全管控和应急救援的各项准备工作,才是保障安全、防控灾害的根本方法。血的教训不可忘,要想悲剧不再重演,必须采用系统思维进行体系建设,利用先进信息通讯技术采用"互联网+"模式建立全国统一的全天候的实时动态监控体系,在规范管理、防患未然的同时,为应急救援工作提供准确信息和合理救援方案。     

基于模糊层次分析法的高楼拆除爆破安全评价

结合茅台镇高层楼房拆除爆破工程实例,利用层次分析法分析拆除爆破施工中影响安全的主要因素,建立对比判断矩阵,运用模糊评判法计算出楼房拆除爆破中布孔是首要关键的工序,亦是影响爆破安全最主要的因素。通过获取各影响因素的权重,能够让管理者在施工中发现主要影响因素并加强安全管理,有效控制各个因素的危险度,从而提高高楼拆除爆破的安全性。模糊综合分析结果表明,拆除爆破重点在于施工人员的管理,同时完善安全防护措施能够使得爆破施工顺利完成。     

基于模糊层次分析法的高楼拆除爆破安全评价

结合茅台镇高层楼房拆除爆破工程实例,利用层次分析法分析拆除爆破施工中影响安全的主要因素,建立对比判断矩阵,运用模糊评判法计算出楼房拆除爆破中布孔是首要关键的工序,亦是影响爆破安全最主要的因素。通过获取各影响因素的权重,能够让管理者在施工中发现主要影响因素并加强安全管理,有效控制各个因素的危险度,从而提高高楼拆除爆破的安全性。模糊综合分析结果表明,拆除爆破重点在于施工人员的管理,同时完善安全防护措施能够使得爆破施工顺利完成。     

Occupational health management system: A study of expatriate construction professionals

Due to its direct impact on the safety and function of organizations, occupational health has been a concern of the construction industry for many years. The inherent complexity of occupational health management presents challenges that make a systems approach essential. From a systems perspective, health is conceptualized as an emergent property of a system in which processes operating at the individual and organizational level are inextricably connected. Based on the fundamental behavior-to-performance-to-outcome (B-P-O) theory of industrial/organizational psychology, this study presents the development of an I-CB-HP-O (Input-Coping Behaviors-Health Performance-Outcomes) health management systems model spanning individual and organizational boundaries. The model is based on a survey of Hong Kong expatriate construction professionals working in Mainland China. Such professionals tend to be under considerable stress due not only to an adverse work environment with dynamic tasks, but also the need to confront the cross-cultural issues arising from expatriation. A questionnaire was designed based on 6 focus groups involving 44 participants, and followed by a pilot study. Of the 500 questionnaires distributed in the main study, 137 valid returns were received, giving a response rate of 27.4%. The data were analyzed using statistical techniques such as factor analysis, reliability testing, Pearson correlation analysis, multiple regression modeling, and structural equation modeling. Theories of coping behaviors and health performance tend to focus on the isolated causal effects of single factors and/or posits the model at single, individual level; while industrial practices on health management tend to focus on organizational policy and training. By developing the I-CB-HP-O health management system, incorporating individual, interpersonal, and organizational perspectives, this study bridges the gap between theory and practice while providing empirical support for a systems view of health management.     

Reliability guarantee framework for the Sichuan–Tibet Railway

The Sichuan–Tibet Railway is facing extraordinary challenges in terms of construction, operation, and maintenance because of its extremely complicated natural environment and geological conditions. Consequently, countermeasures are necessary and urgent to ensure its safety and reliability in the whole life cycle. This study proposes a novel reliability framework to guarantee the ideal operation state of the Sichuan–Tibet Railway. Reliability application in many fields are summarized, including military equipment, rail locomotive, and railway engineering. Given the fact that the Sichuan–Tibet Railway is a complex giant system, Nine-Connotation was summarized (i.e., safety, inherent reliability, testability, maintainability, supportability, environmental adaptability, predictability, resilience, and durability) under the goal of optimizing the operational efficiency. On the basis of the concept of the Nine-Connotation and the understanding of reliability transmission mechanism, the framework of reliability for the Sichuan–Tibet Railway was established, which can facilitate a comprehensive and real-time evaluation of all situations with a clear hierarchy. The proposed framework is composed of a resilience management system, an integrated technology system, and a dynamic reliability assessment system. The pathway for its application on railway construction was developed in this study. The proposed framework can assist in well-informed decisions for the construction, as well as the operation of the Sichuan–Tibet Railway. On the basis of a top–down design concept for the first time, this study emphasizes the railway’s availability and validity to complete the assigned tasks as a whole, that is, operational efficiency. It also shows the reliability transmission and control mechanism of the railway’s giant complex system, innovating and establishing the management principle of great safety and great reliability over the life cycle.     

A system dynamics approach for modeling construction workers’ safety attitudes and behaviors

Construction accidents are caused by an unsafe act (i.e., a person's behavior or activity that deviates from normal accepted safe procedure) and/or an unsafe condition (i.e., a hazard or an unsafe mechanical or physical environment). While there has been dramatic improvement in creating safer construction environments, relatively little is known regarding the elimination of construction workers’ unsafe acts. To address this deficiency, this paper aims to develop a system dynamics (SD)-based model of construction workers’ mental processes that can help analyze the feedback mechanisms and the resultant dynamics regarding the workers’ safety attitudes and safe behaviors. The developed model is applied to examine the effectiveness of three safety improvement policies: incentives for safe behaviors, and increased levels of communication and immersion in accidents. Application of the model verifies the strong potential of the developed model to provide a better understanding of how to eliminate unsafe acts, and to function as a robust test-bed to assess the effectiveness of safety programs or training sessions before their implementation.     

Managing risk dormancy in multi-team work: application of time-dependent success-and-safety assurance methodology

The success and safety of many of today's industrial activities, such as constructing power plants, transmission lines and civil engineering objects, is often influenced by situations, when successful and safe work completion is associated with the implementation of various more or less complex multi-team (MT) layouts. Multi-team effort is characterised by the presence and interaction of numerous, not necessarily concurrent time- and space-constrained interfering activities, as well as by dormant risks. Such risks might threaten the fulfilment of the general task carried out by the main team and/or by other teams on the construction site. This analysis addresses the role of the dormant risks during the fulfilment of a non-simultaneous MT work. The objective of the analysis is to suggest an effective and physically meaningful probabilistic predictive model. The model is aimed at the understanding, quantification and effectively managing the dynamics of the system of interest. The emphasis is on the role of possible dormancies. The study is an extension of the authors’ earlier research on spatial and time dimensions in the addressed problem. The study extends the risk management approach to a holistic level.

Relevance to human factors/ergonomics theory

This article characterises the risk dormancy phenomenon to be considered as a proper way of taking into account multi-team (MT) aspects in the occupational safety research. Furthermore, a holistic perception of MT functional complexity allows for a generalised view of MT mutual interaction instead of focusing in the single team behaviour.     

Predicting crash likelihood and severity on freeways with real-time loop detector data

Real-time crash risk prediction using traffic data collected from loop detector stations is useful in dynamic safety management systems aimed at improving traffic safety through application of proactive safety countermeasures. The major drawback of most of the existing studies is that they focus on the crash risk without consideration of crash severity. This paper presents an effort to develop a model that predicts the crash likelihood at different levels of severity with a particular focus on severe crashes. The crash data and traffic data used in this study were collected on the I-880 freeway in California, United States. This study considers three levels of crash severity: fatal/incapacitating injury crashes (KA), non-incapacitating/possible injury crashes (BC), and property-damage-only crashes (PDO). The sequential logit model was used to link the likelihood of crash occurrences at different severity levels to various traffic flow characteristics derived from detector data. The elasticity analysis was conducted to evaluate the effect of the traffic flow variables on the likelihood of crash and its severity.The results show that the traffic flow characteristics contributing to crash likelihood were quite different at different levels of severity. The PDO crashes were more likely to occur under congested traffic flow conditions with highly variable speed and frequent lane changes, while the KA and BC crashes were more likely to occur under less congested traffic flow conditions. High speed, coupled with a large speed difference between adjacent lanes under uncongested traffic conditions, was found to increase the likelihood of severe crashes (KA). This study applied the 20-fold cross-validation method to estimate the prediction performance of the developed models. The validation results show that the model's crash prediction performance at each severity level was satisfactory. The findings of this study can be used to predict the probabilities of crash at different severity levels, which is valuable knowledge in the pursuit of reducing the risk of severe crashes through the use of dynamic safety management systems on freeways.     

Toward an understanding of the impact of production pressure on safety performance in construction operations

It is not unusual to observe that actual schedule and quality performances are different from planned performances (e.g., schedule delay and rework) during a construction project. Such differences often result in production pressure (e.g., being pressed to work faster). Previous studies demonstrated that such production pressure negatively affects safety performance. However, the process by which production pressure influences safety performance, and to what extent, has not been fully investigated. As a result, the impact of production pressure has not been incorporated much into safety management in practice. In an effort to address this issue, this paper examines how production pressure relates to safety performance over time by identifying their feedback processes. A conceptual causal loop diagram is created to identify the relationship between schedule and quality performances (e.g., schedule delays and rework) and the components related to a safety program (e.g., workers’ perceptions of safety, safety training, safety supervision, and crew size). A case study is then experimentally undertaken to investigate this relationship with accident occurrence with the use of data collected from a construction site; the case study is used to build a System Dynamics (SD) model. The SD model, then, is validated through inequality statistics analysis. Sensitivity analysis and statistical screening techniques further permit an evaluation of the impact of the managerial components on accident occurrence. The results of the case study indicate that schedule delays and rework are the critical factors affecting accident occurrence for the monitored project.     

Geode: Optimizing data flow representation techniques in a network information system

The Informetrics Research Group (CERESI/CNRS) was recently created by the Mission for Scientific and Technical Information and Communication of the CNRS. CERESI's goal is to study the impact of computer supported information exchanges on the social processes underlying the construction of scientific knowledge. A better understanding of this impact should help in designing and building scientific and technical information management systems. In this paper, we will focus on one aspect of our work: mapping science and technology in order to build dynamic representations of science and technology.Presented at the Fourth International Conference on Bibliometrics, Informetrics and Scientometrics in Berlin (Germany), September 11–15, 1993.     

Mechanistic-based comparisons of stabilised base and granular surface layers of low-volume roads

Granular surface and base layers of low-volume roads (LVRs) are frequently subjected to severe damage that adversely affects safety and requires regular repair and maintenance. Various stabilisation methods have been evaluated for mitigating damage and improving serviceability of LVR systems. However, few well-documented comparisons exist of the field mechanical performance, durability and construction costs of different stabilisation methods under the same set of geological, climate, and traffic conditions. Therefore, the present study was conducted to identify the most effective and economical among several stabilisation methods for repairing or reconstructing granular surface and base layers of LVRs. In this study, a range of promising technologies from a comprehensive literature review was selected and examined using field demonstration sections. A total of nine geomaterials, three chemical stabilisers, and three types of geosynthetics were used to construct various test sections over a 3.22 km stretch of granular-surfaced road. Extensive falling weight deflectometer (FWD) and dynamic cone penetrometer tests were performed to evaluate the multilayered elastic moduli and strengths of the various sections. This paper details the design and construction of each test section, compares the as-constructed mechanistic performance of all test sections, and assesses stiffness changes of several sections one year after construction. To provide a statistical basis for the comparisons, a pairwise multiple-comparison procedure applied for unequal sample sizes and variances and the paired t-test were used to analyse the FWD test results, demonstrating that the performance measures of the various sections were significantly different.