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.     

A survey on management perspectives of the state of workplace health and safety practices in Kenya.

A baseline survey was conducted in 1995 on management perspectives of occupational health and safety (OHS) structures and practices in Kenya. This was achieved by interviewing management and supervisory staff attending 1 week multi-disciplinary courses that were organized by the Federation of Kenya Employers (FKE) and the International Labour Office (ILO) at hotel venues in Kenya. The purpose of the survey was to gain some insight into work safety conditions in Kenya and to assess the potential for a new OHS manual to meet existing knowledge gaps. The manual was locally developed in 1993/4 by Kenyan OHS experts in collaboration with colleagues from the Swedish National Institute for Working Life. Results of the survey from 65 participants indicated that most workplace managers were not familiar with the Kenyan work safety legislation. Work injuries were largely attributable to working with dangerous machinery. Occupational diseases and HIV/AIDS were cited as other causes of workplace morbidity and mortality. Although most respondents (70%) were satisfied with their work safety conditions, only 37% said their workplaces were annually audited by labour inspectors while 45% said injured workers were not treated well by management. Many workplaces (65%) violated the mandatory legal requirement on the establishment of health and safety committees. The OHS resource person and course content were rated highly by most respondents (96%). The foregoing results provided the basis of a needs analysis for future OHS programs in Kenya.     

Proposal of a risk-factor-based analytical approach for integrating occupational health and safety into project risk evaluation

Excluding occupational health and safety (OHS) from project management is no longer acceptable. Numerous industrial accidents have exposed the ineffectiveness of conventional risk evaluation methods as well as negligence of risk factors having major impact on the health and safety of workers and nearby residents. Lack of reliable and complete evaluations from the beginning of a project generates bad decisions that could end up threatening the very existence of an organization.     

Dual-effects of core enterprise management and media attention on occupational health and safety of small and medium suppliers in China

This study examines the construction of an occupational health and safety (OHS) governance model for small- and medium-sized suppliers (SMSs) impacted by the dual effects of core enterprises' management and media attention. The objective of this research is to improve the social governance effect of SMSs' OHS. Drawing on evolutionary economics, an evolutionary game model with three main players—core enterprises, SMSs, and media—is established, and the conditions of each entity's evolutionary stability strategy are analyzed. The results show that the evolution trend for any party is closely related to the strategic choices of the other two parties. Further, a model for SMSs' OHS governance with focus on core enterprise management and media attention can be effectively built by reducing the costs of core enterprise management, enhancing the probability of accurate media reporting, decreasing the OHS input cost of SMSs, increasing the expected exposure returns of the media, and reducing the media's investigation cost. This study is the first to consider the important influence of core enterprises and the media on SMSs' OHS behavior, which bridges the research gap not only from a theoretical perspective, but also a practical one.     

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.     

Integration of occupational health and safety in the facility layout planning,part II: design of the kitchen of a hospital

Facility layout design has an important effect on the performance of manufacturing systems. It intends to determine relative location of departments and machines within a plant. A good layout design must ensure that a set of criteria and objectives are met and optimised, e.g. area requirements, cost, communication and safety. The most common objective used in facility planning methods is to minimise the transportation cost. However, factors such as the plant safety, flexibility for future design changes, noise and aesthetics must be considered as well. In this paper, a case study is carried out to investigate the safety concerns in facility layout design. In this regard, a facility layout planning methodology, integrating occupational health and safety (OHS) is presented. This methodology considers transportation cost as well as safety in the facility design. By this means, OHS issues are considered at the design stage of the facility. In other words, this research demonstrates the improvements in the layout design by integrating safety aspects.     

A hybrid simulation approach for integrating safety behavior into construction planning: An earthmoving case study

One of the key challenges in improving construction safety and health is the management of safety behavior. From a system point of view, workers work unsafely due to system level issues such as poor safety culture, excessive production pressure, inadequate allocation of resources and time and lack of training. These systemic issues should be eradicated or minimized during planning. However, there is a lack of detailed planning tools to help managers assess the impact of their upstream decisions on worker safety behavior. Even though simulation had been used in construction planning, the review conducted in this study showed that construction safety management research had not been exploiting the potential of simulation techniques. Thus, a hybrid simulation framework is proposed to facilitate integration of safety management considerations into construction activity simulation. The hybrid framework consists of discrete event simulation (DES) as the core, but heterogeneous, interactive and intelligent (able to make decisions) agents replace traditional entities and resources. In addition, some of the cognitive processes and physiological aspects of agents are captured using system dynamics (SD) approach. The combination of DES, agent-based simulation (ABS) and SD allows a more “natural” representation of the complex dynamics in construction activities. The proposed hybrid framework was demonstrated using a hypothetical case study. In addition, due to the lack of application of factorial experiment approach in safety management simulation, the case study demonstrated sensitivity analysis and factorial experiment to guide future research.     

Catastrophe modeling of the accident process: evaluation of an accident reduction program using the occupational hazards survey

The report details a catastrophe theory model of the accident process with empirical validation. According to the cusp model, two distinct levels of risk can be observed for a distribution of group accident rates, one at 0.0 Occupational Safety and Health Association (OSHA)-reportable accidents per 100 person-years of exposure and one at 11.5. Changes within or between the two levels are determined by two control parameters: environmental hazard (asymmetry) and operator load (bifurcation). The sample consisted of 68 work groups from 8 Milwaukee-Chicago area sheet metal mills and foundries who completed the Occupational Hazards Survey (OHS). The OHS contributed six bifurcation variables (safety management, life stress, physical stress anxiety, beliefs about accident control, and experience) and two asymmetry variables (environmental hazards and danger). All organizations received an interpretive report of their survey responses with recommendations for accident control, and had held their reports for two to nine months at the time the follow-up accident rate data were collected. There were two additional bifurcation variables: months holding report and group size. Regression analysis determined that the cusp model (R2 = .42) was more than twice as accurate as the best log-linear or linear alternative. Accidents were successfully controlled by safety managers' attention to recommendations produced by the OHS analysis. Catastrophe theory provided some novel insights regarding the linkage between predictor variables and actual behavior. Research has shown that a substantial percentage of occupational accidents are the result of human error. In an effort to explain and predict such errors in a systematic manner, an accident process model based on the cusp catastrophe is developed and tested. The model offers several unique and useful properties: (1) It proposes that changes in accident rates for work groups are the result of a nonlinear dynamic process. (2) The distribution of accident rates is bimodal, with one model near zero and the other at some higher level. (3) Changes in accident rates are predicted from four sources: (i) ambient danger and hazard levels, (ii) variables that impact upon human performance capability, (iii) initial accident rates, and (iv) the mathematical function that interrelates those variables. (4) The mathematical model has inherent properties that allow for causal inference. Environmental and human performance factors can be operationalized as sets of more specific variables. In this application. The Occupational Hazards Survey was used to gather data from mill and foundry workers pertaining to hazards and dangers, adequacy of safety management, stress, anxiety, and beliefs about accident control.(ABSTRACT TRUNCATED AT 400 WORDS)     

Barriers to the implementation of management systems: lessons from the past.

There is a substantial body of evidence, both empirical and anecdotal, concerning factors associated with the success and failure of management systems. Given the increasing interest in management systems for occupational health and safety, quality, and the environment, it is worth looking at some of these factors in order to learn from them and plan for the future. One of the most comprehensive sources of information about factors that can make a management system succeed or fail lies in the material written about systems that improve the quality of products and services. Such systems were extremely widespread during the 1970s and 1980s but are now much less often cited or studied by Australian organisations. One of the reasons underlying the present relative lack of emphasis is that such programs, both here and overseas, experienced a failure rate of between 85% and 95%. While it may seem unlikely that occupational health and safety (OHS) and environmental management systems will experience similar failure rates, it is still worthwhile to look at what went wrong with other systems and to learn from these experiences.     

Identifying behaviour patterns of construction safety using system archetypes

Construction safety management involves complex issues (e.g., different trades, multi-organizational project structure, constantly changing work environment, and transient workforce). Systems thinking is widely considered as an effective approach to understanding and managing the complexity. This paper aims to better understand dynamic complexity of construction safety management by exploring archetypes of construction safety. To achieve this, this paper adopted the ground theory method (GTM) and 22 interviews were conducted with participants in various positions (government safety inspector, client, health and safety manager, safety consultant, safety auditor, and safety researcher). Eight archetypes were emerged from the collected data: (1) safety regulations, (2) incentive programs, (3) procurement and safety, (4) safety management in small businesses (5) production and safety, (6) workers’ conflicting goals, (7) blame on workers, and (8) reactive and proactive learning. These archetypes capture the interactions between a wide range of factors within various hierarchical levels and subsystems. As a free-standing tool, they advance the understanding of dynamic complexity of construction safety management and provide systemic insights into dealing with the complexity. They also can facilitate system dynamics modelling of construction safety process.     

Understanding social impacts by using new variables and a causal model diagram in New England fisheries

This paper reviews the applicability of the Social Impact Assessment (SIA) process within the framework of US national environmental policy used in New England fishery management. Its aim is to develop a new approach to SIA that goes beyond identifying impacts through guidelines, to include an understanding and portrayal of causality and emergent relationships. The emphasis is on creating a new list of variables identifying social impacts and social change processes. These variables are used in a causal chain model to diagrammatically portray impact dynamics over time and scale. This approach intends to fulfill a need for an accurate and timely methodology used in fishery management to identify potential social impacts of management actions, in order to achieve ecological and socioeconomic sustainability.     

轻量化材料焊接车间智能化要素分析

本文从轻量化材料焊接最终目标和需求、数字化和智能化技术发展趋势、焊接车间柔性构建三个维度出发,结合先进制造车间智能化和焊接工艺数字化技术发展趋势,分析得出了轻量化材料焊接车间智能化需满足的焊接控制管理实时化、焊接过程质量控制闭环化、焊接性分析数据化、焊接工艺分析智能化、快速互换装夹(柔性化)、焊缝质量检测工具化、焊接生产管理数字化、焊接基础数据库无纸化八大基本要素,并对这些要素分别进行了阐述,相关结论可以作为焊接车间智能化改造或新建的参考。     

Critical factors and paths influencing construction workers’ safety risk tolerances

While workers’ safety risk tolerances have been regarded as a main reason for their unsafe behaviors, little is known about why different people have different risk tolerances even when confronting the same situation. The aim of this research is to identify the critical factors and paths that influence workers’ safety risk tolerance and to explore how they contribute to accident causal model from a system thinking perceptive. A number of methods were carried out to analyze the data collected through interviews and questionnaire surveys. In the first and second steps of the research, factor identification, factor ranking and factor analysis were carried out, and the results show that workers’ safety risk tolerance can be influenced by four groups of factors, namely: (1) personal subjective perception; (2) work knowledge and experiences; (3) work characteristics; and (4) safety management. In the third step of the research, hypothetical influencing path model was developed and tested by using structural equation modeling (SEM). It is found that the effects of external factors (safety management and work characteristics) on risk tolerance are larger than that of internal factors (personal subjective perception and work knowledge & experiences). Specifically, safety management contributes the most to workers’ safety risk tolerance through its direct effect and indirect effect; while personal subjective perception comes the second and can act as an intermedia for work characteristics. This research provides an in-depth insight of workers’ unsafe behaviors by depicting the contributing factors as shown in the accident causal model developed in this research.     

Working in light vehicles--a review and conceptual model for occupational health and safety

Occupational light vehicle (OLV) use is the leading cause of work related traumatic deaths in Westernised countries. Previous research has focused primarily on narrow contexts of OLV-use such as corporate fleet vehicles. We have proposed a comprehensive systems model for OLV-use to provide a framework for identifying research needs and proposing policy and practice interventions. This model presents the worker as the locus of injury at the centre of work- and road-related determinants of injury. Using this model, we reviewed existing knowledge and found most studies focused only on company car drivers, neglecting OLV-users in non-traditional employment arrangements and those using other vehicle types. Environmental exposures, work design factors and risk and protective factors for the wider OLV-user population are inadequately researched. Neither road- nor work-related policy appropriately addresses OLV-use, and population surveillance relies largely on inadequate workers compensation insurance data. This review demonstrates that there are significant gaps in understanding the problem of OLV-use and a need for further research integrating public health, insurance and road safety responses. The model provides a framework for understanding the theory of OLV-use OHS and guidance for urgently needed intervention research, policy and practice.     

Investigating the multi-causal and complex nature of the accident causal influence of construction project features

Construction project features (CPFs) are organisational, physical and operational attributes that characterise construction projects. Although previous studies have examined the accident causal influence of CPFs, the multi-causal attribute of this causal phenomenon still remain elusive and thus requires further investigation. Aiming to shed light on this facet of the accident causal phenomenon of CPFs, this study examines relevant literature and crystallises the attained insight of the multi-causal attribute by a graphical model which is subsequently operationalised by a derived mathematical risk expression that offers a systematic approach for evaluating the potential of CPFs to cause harm and consequently their health and safety (H&S) risk implications. The graphical model and the risk expression put forth by the study thus advance current understanding of the accident causal phenomenon of CPFs and they present an opportunity for project participants to manage the H&S risk associated with CPFs from the early stages of project procurement.     

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.     

The Four‐Domain Development Diagram: A Guide for Holistic Design of Effective Learning Experiences for the Twenty‐first Century Engineer

The twenty‐first century challenges engineering educators to design learning experiences to strategically and holistically target students' development, including cognitive, psychomotor, social and affective domains. We propose a guide for the design process. The Four‐Domain Development Diagram (4DDD) is a synthesis of learning theory and empirical data. This guide maps the relationships among the major factors that influence learning and presents them in the form of a causal loop diagram, a tool used by systems dynamicists to show how changes in important factors affect other factors within the system. In this paper, we present the theoretical and empirical basis of the 4DDD. We also describe how the 4DDD can be used as a design guide for instructional changes that promote more effective learning experiences for the broader cognitive, social, affective, and psychomotor development required of today's engineering graduate.     

Improvisation: theory,measures and known influencing factors

Interest in the potential of improvisation to enhance safety outcomes in safety critical situations has been increasing; however, improvisation also has the potential to make emergency situations worse rather than better. If organisations are to capitalise on improvisation's potential to produce safety benefits, a model of the factors that influence its effectiveness in safety critical situations is needed. This review draws together what is currently known about the factors influencing improvisation and the methods used to examine them. The review reveals that, unlike most contemporary ergonomics concepts, as yet no research has examined factors beyond organisational boundaries or examined the interactions of factors across different systems levels, both integral components of systems-based models. In closing, discussion is presented on the most appropriate research agenda for enhancing understanding of improvisation and its influencing factors.     

Integrating occupational health and safety in facility layout planning,part I: methodology

An influential factor affecting the efficiency of a manufacturing facility is its layout. In a production facility, measure for efficiency can be based on the total cost of transporting the items between different departments and throughout the facility. However, other factors may influence efficiency of the manufacturing facility too. As such are: supporting the organisation's vision through improved material handling, material flow and control; effectively assigning people, equipment, space and energy; minimising capital investment; adaptability and ease of maintenance; as well as providing for employee safety and job satisfaction. By incorporating health and safety measures in the initial design of a facility layout, the organisation may avoid money and manpower loss resulting from industrial accidents. This paper proposes a facility layout planning methodology which integrates the occupational health and safety (OHS) features in the early design of a facility layout. The model considers transportation cost in the facility as well as safety concerns. By this means, the OHS issues are reflected prior to the construction of a facility.     

Automated digital cause-and-effect diagrams to assist causal analysis in problem-solving: a data-driven approach

Causal analysis is an integral part of product quality problem-solving (QPS). Quality management within the manufacturing industry has generated a considerable amount of QPS data; while this implies a historical and extensive body of QPS experience, these valuable empirical data are not being fully utilised. Therefore, the current study proposes a method by which to mine know-why from historical empirical data, and it develops an approach for constructing digital cause-and-effect diagrams (CEDs). The K-means algorithm is first adopted to cluster the problems and causes. The random forest classifier is then selected to classify cause text into the main cause categories, which manifest as ‘rib branches’ in the CED. Based on the clustering and classification results, we obtain an abstract cause-and-effect diagram (ACED) and a detailed cause-and-effect diagram (DCED). We use the quality data of an automotive company to validate the method, and we additionally undertake a pilot run of the Fishbone Next system to demonstrate how users can obtain these two CEDs to support causal analysis in QPS. The results show that the proposed approach efficiently constructs a digital CED and thus provides quality management problem-solvers with decision support to derive the potential causes of problems, thereby improving the efficiency and effectiveness of their causal analysis initiatives.