Knowledge-based energy damage model for evaluating Occupational Health and Safety (OHS) construction risks in Malaysia

The construction industry is renowned as a high-risk industry which involves complex, time consuming design and construction processes characterized by unforeseen circumstances and which has been plagued with accidents for a long time (Ren, 1994). Eliminating the risk of adverse occurrences is essential in order to provide a safe and healthy working environment on construction sites. This paper presents an initial concept for the comparative evaluation of OHS risks for different construction approaches. The model uses a combination of the 'argument tree' concept and 'energy damage model' theory. The assessment process provides a perspective on how the design decisions can impact on OHS for the workers. The 'delivery' stage of two Malaysia housing projects, procured using both conventional and industrialised methods, are utilized to illustrate the model

Building a safety culture: the importance of "shared mental models" in the Australian construction industry

Managers of construction organizations often speak about the inmportance of OHS. Some organizations move beyond the rhetoric to implement OHS management systems, supported by programmes of OHS training and audits. Yet in the face of deadlines or budgetary pressures, managers at all levels of construction organizations sometimes change their priorities to pursue performance in the traditional areas of cost, time and quality - at the expense of OHS. It would be rare for a manager to openly diminish the importance of understanding about how important OHS 'really is'. This paper discusses research currently underway in the Australian construction industry into the role played by managers at different levels in creating OHS sub-cultures in construction organizations. The paper explores how the existence of these sub-cultures should be identified and managed to create shared mental models of OHS within participating organizations

Designing for construction workers' occupational health and safety: A case study of socio-material complexity

Drawing upon an empirical analysis of the design and construction of a food processing facility, a theoretical understanding of the impact of design decision-making on the occupational health and safety (OHS) of construction workers is developed. It is argued that current policy and legislative approaches to Construction Hazard Prevention through Design (CHPtD) are inherently limited because they do not adequately reflect the socio-material complexity of decision-making in construction design. Specifically, the simplistic attribution of responsibility to a single socio-technical actor, 'the designer', does not reflect the multiple and disparate influences that impact upon OHS outcomes. Nor do existing CHPtD policy frameworks, management processes and tools recognize the manner in which the interactions and associations between relevant project stakeholders and various non-human artefacts shape (and are also influenced by) the evolution of design decisions. Drawing on actor-network theory (ANT) and using embedded units within a case study approach, the interactions between human actors and non-human artefacts are explored in relation to the design of four components of the food processing facility. The way in which design decisions unfolded and shaped OHS experiences during the construction stage of the project is revealed. The research highlights limitations inherent in current approaches to the management of CHPtD and the need to develop a more robust theoretically based approach to integrating OHS considerations into construction design practice

The impact of construction commencement intervals on residential production building

One model of operation that production builders can use is continuous construction. They build typical house models and generally work with the same subcontractors. In this continuous operation, an order from the sales department triggers the process, which only commences construction when the first required crew becomes available. In this system the decision to commence construction relies on the readiness of the first activity. However the effects of this decision on the whole construction process are often ignored. This research aims to shed light on the importance of construction commencement decisions by highlighting the consequences of this decision on the whole production system

Do perceptions of supervisors’ safety responses mediate the relationship between perceptions of the organizational safety climate and incident rates in the construction supply chain?

A multilevel safety climate survey was conducted in three Australian organizations in the construction supply chain. A principal components analysis (with varimax rotation) yielded six distinct safety climate factors reflecting aspects of the organizational safety response (OSR), supervisors’ safety response (SSR), and coworkers’ safety response (CSR). Perceptions of top management’s commitment to safety (an aspect of OSR) and supervisors’ safety expectations (an aspect of SSR) were both significantly and inversely correlated with the combined medical treatment and lost time injury rate of workgroups in the analysis. Further, regression analysis revealed that perceptions of supervisors’ safety expectations fully mediated the relationship between perceptions of top management’s commitment to safety and the workgroup injury frequency rate. The results highlight the critical role played by first-level supervisors in acting as the conduit through which organizational safety priorities are communicated to the workforce

Off-site manufacture in Australia: Current state and future directions

Although numerous reports have been produced in the UK on the state of off-site manufacture adoption, no prominent studies exist for the Australian context. This scoping study that lead to this publication is an essential component on which to build any initiatives that can take advantage of the benefits of OSM in construction. It confirms the benefits and identifies the real and perceived barriers to widespread adoption of OSM, and identifies opportunities for future investment and research

A new approach for modelling variability in residential construction projects

The construction industry is plagued by long cycle times caused by variability in the supply chain. Variations or undesirable situations are the result of factors such as non-standard practices, work site accidents, inclement weather conditions and faults in design. This paper uses a new approach for modelling variability in construction by linking relative variability indicators to processes. Mass homebuilding sector was chosen as the scope of the analysis because data is readily available. Numerous simulation experiments were designed by varying size of capacity buffers in front of trade contractors, availability of trade contractors, and level of variability in homebuilding processes. The measurements were shown to lead to an accurate determination of relationships between these factors and production parameters. The variability indicator was found to dramatically affect the tangible performance measures such as home completion rates. This study provides for future analysis of the production homebuilding sector, which may lead to improvements in performance and a faster product delivery to homebuyers

Improving construction productivity: implications of even flow production principles

Subcontracting has been widely used in order to address the high level of variability and associated risks in the complex configuration of residential construction production systems. However, the explosion of subcontracting and the parade of trades have made the construction operations very fragmented, leading to lack of predictability and adequate control on schedules and quality. The present paper proposes a set of system configurations for residential construction. On this basis, after an extensive review of the efforts to model construction production problems, several discrete event simulation models have been developed so as to assess tangible performance measures. Comparing and contrasting the results, two attributes of the system were found to be critical to yield better performance measures. In the proposed flexible system design, fewer cross-trained subcontractors undertake integrated work processes. Also, the number of houses under construction does not grow infinitely and is proportional to the system capacity

Group-level safety climate in the Australian construction industry: Within-group homogeneity and between-group differences in road construction and maintenance

In modern organizations it is overly simplistic to assume that a uniform, organization-wide climate for safety develops. Workgroup-level safety climates are more likely to arise in decentralized organizations and their influence on occupational health and safety (OHS) behaviour is likely to be stronger when work is non-routine, as in construction. The existence of workgroup-level safety climates was examined in the Australian construction industry. A group-level safety climate survey was conducted in a road maintenance and construction organization. The clear factorial structure produced in a larger sample of Australian defence logistics workers was not replicated and factors splintered, possibly due to the subject-to-item ratio in the construction study. However, the internal reliability consistency of the factors produced in the earlier pilot study was found to be acceptable for the construction industry data. Two requisite conditions for the existence of group-level safety climates, i.e. (1) within-group homogeneity; and (2) between-group variation, were satisfied within the road construction and maintenance organization. The results indicate that distinct workgroup safety climates exist in construction, providing a theoretical explanation for why some workgroups perform better in OHS than others, despite having similar risk exposure

Framework for improving workflow stability: deployment of optimized capacity buffers in a synchronized construction production

Construction sites are dynamic environments due to the influence of variables such as changes in design and processes, unsteady demand, and unavailability of trades. These variables adversely affect productivity and can cause an unstable workflow in the network of trade contractors. Previous research on workflow stability in the construction and manufacturing domains has shown the effectiveness of 'pull' production or 'rate driven' construction. Pull systems authorize the start of construction when a job is completed and leaves the trade contractor network. However, the problem with pull systems is that completion dates are not explicitly considered and therefore additional mechanisms are required to ensure the due date integrity. On this basis, the aim of this investigation is to improve the coordination between output and demand using optimal-sized capacity buffers. Towards this aim, production data of two Australian construction companies were collected and analyzed. Capacity and cost optimizations were conducted to find the optimum buffer that strikes the balance between late completion costs and lost revenue opportunity. Following this, simulation experiments were designed and run to analyze different 'what-if' production scenarios. The findings show that capacity buffers enable builders to ensure a desired service level. Size of the capacity buffer is more sensitive to the level of variability in contractor processes than other production variables. This work contributes to the body-of-knowledge by improving production control in constructionanddeploymentof capacity buffers to achieve a stableworkflow.In addition, constructioncompaniescanuse the easy-to-use framework tested in this study to compute the optimal size for capacity buffers that maximizes profit and prevents late completions