Mehrdad Arashpour

Analysis of workflow variability and its impacts on productivity and performance in construction of multistory buildings

AbstractThe meeting of milestones presents a constant challenge in construction projects. One root cause behind this challenge is the presence of variability in the project workflow. In fact, impacts of variability at both the trade contractor level and project level remain difficult to manage. This paper aims to analyze impacts of variability in the workflow caused by rework and fluctuating work quantities. Toward this end, production data of two residential construction companies were collected, and a mixed method of mathematical and simulation modeling was used to analyze performance and productivity at both the trade and project levels. Performance metrics such as completion times, work-in-process levels, and delays were then measured in different real-life production scenarios. The findings clearly show that the workflow variability significantly downgrades performance metrics by causing inflated completion times, longer queues of uncompleted jobs, and excessive delays, resulting in productivity loss...

Analysis of Disruptions Caused by Construction Field Rework on Productivity in Residential Projects

Operational performance in residential construction production systems is assessed based on measures such as average house-completion time, number of houses under construction, lead time, and customer service. These systems, however, are prone to nonuniformity and interruptions caused by a wide range of variables such as inclement weather conditions, accidents at worksites, fluctuations in demand for houses, and rework. The availability and capacity of resources therefore are not the sole measures for evaluating construction production systems capacity, especially when rework is involved. The writers’ aim is to investigate the effects of rework timeframe and frequency/length on tangible performance measures. Different call-back timeframes for rework and their impact on house-completion times are modeled and analyzed. Volume home-building was chosen as the industry sector studied in the research reported in this paper because it is a data-rich environment. The writers designed several experiments to model on time, late, and early call-back timeframes in the presence of rework with different length and frequency. Both mathematical modeling and discrete-event simulation were then used to compare and contrast outputs. The measurements showed that the average completion time is shorter in systems interrupted by frequent but short rework. In other words, a smaller downstream buffer between processes is required to avoid work starvation than those systems affected by infrequent but long interruptions. Early call-backs for rework can significantly increase the number of house completions over the long run. This indicates that there is an opportunity for the mass house-building sector to improve work practice and project delivery by effectively managing rework and its related variables. The research reported in this paper builds on the current body-of-knowledge by applying even-flow production theory to the analysis of rework in the residential construction sector, with the intention of ensuring minimal disruption to construction production process and improving productivity.

Enhancing collaboration in BIM-based construction networks through organisational discontinuity theory: a case study of the new Royal Adelaide Hospital

ABSTRACT This paper discusses a case study of Australia’s most technologically advanced health facility to address an identified gap in the body of the knowledge. That is, no comprehensive study has hitherto attempted to draw upon virtual team working theories to enhance collaboration in BIM-based construction networks (BbCNs). In response to this, the present study seeks to raise awareness of organisational discontinuity theory (ODT) as a recent theory for virtual teams, which enables BbCNs to embrace collaboration. To this end, the major challenges encountered and corresponding solutions adopted on a mega-project have been closely monitored and investigated. The study contributes to the field through the conceptualisation of typical barriers to collaboration in BbCNs from the perspective of ODT. Additionally, the discussions presented outline practical implications by demonstrating how the identified issues of collaboration in BbCNs could be effectively dealt with.

Quantitative analysis of rate-driven and due date-driven construction: production efficiency, supervision, and controllability in residential projects

AbstractConcerns about production efficiency, quality, and affordability in the residential construction indicate there may be benefits in adopting alternative production control strategies to those traditionally used. Reducing adverse effects of exogenous variability in demand and endogenous variability in process are the ultimate goals of production control strategies. For residential construction this means controlling the number of houses under construction and controlling the start rate of new house constructions. The aim of this investigation is to compare and contrast the outcomes of these two production management strategies. Production data of two volume house builders in Victoria and Queensland, Australia, were collected. Tangible performance metrics from the builders were analyzed and compared using the principles of queuing theory. Then numerous simulation experiments were designed and run to analyze different what-if scenarios in the building environment. A special purpose simulation template...

Role of Simulation in Construction Processes – Harmony in Capturing Resources

The idleness of equipment-oriented and labor-intensive resources causes productivity losses in construction systems. The aim of this paper is to use discrete-event simulation to determine the system sensitivity to resource level variations. The wall cladding process of ASEMAN Hotel was analyzed to investigate the interaction of three hoists and eight cladding installation teams. A MicroCYCLONE model was developed based on the work task durations observed in the field. Sensitivity analysis of the system revealed the productivity level and idle time of resources over two runs of simulation. The results indicate that different types of resources can be balanced during the preplanning phase of the project by means of construction operation simulation.

Optimal process integration architectures in off-site construction: Theorizing the use of multi-skilled resources

ABSTRACT The architecture, engineering and construction industry has long dealt with problems such as schedule and budget overruns, quality and safety issues, and low productivity. Off-site construction, which is a hybrid of manufacturing and construction, has significant potential to address industry’s endemic problems. However, off-site construction has been criticized for replicating the traditional subcontracting approach and therefore fragmented practice in the construction industry. The current research focuses on process integration and cross-training of multi-skilled resources as a solution to the aforementioned problem. To identify optimal process integration architectures for off-site construction, production data of three off-site manufacturers were analyzed by using a hybrid of fuzzy theory and the technique for order of preference by similarity to ideal solution. Findings reveal that process integration architectures transferring excess capacity from under-utilized to over-utilized resources in direct or indirect pathways are preferable in terms of satisfying decision criteria such as time and cost of cross-training, skill transferability, compliance with network logic, and safety considerations. The study contributes to the off-site construction literature by providing insight into dynamics of using multi-skilled resources. It also contributes to practice by developing a customizable and user-friendly framework for off-site production managers in order to identify the optimal process integration architecture in their own production scenarios.

An integrated model for factors affecting construction and demolition waste management in Iran

Purpose Factors influencing management of construction and demolition (C&D) waste within the Iranian context have yet to be investigated. The purpose of this paper is to define and address this knowledge gap, through development of a model to map the associations among the primary factors affecting C&D waste at project, industry and national levels. Design/methodology/approach A conceptual model is developed based on synthesising the findings of available studies on factors affecting C&D waste with a focus on developing countries. For collecting data, the study drew upon a questionnaire survey of 103 Iranian construction practitioners. The strength and significance of associations among these factors to modify and validate the model were assessed using the structural equation modelling-partial least squares approach. Findings Major factors affecting C&D waste management and their level of importance were identified at project, industry and national levels. Results clearly showed that the government should review regulations pertaining to C&D waste management and make sure they are implemented properly. The “polluter pays principle” is a useful guide in devising effective policies and regulations for the Iranian context. Originality/value This study contributes to the field through presenting the first major study on C&D waste management in Iran. The study provides a picture of C&D waste management status quo in Iran and encapsulates the factors affecting C&D waste management in the Iranian context at different levels within an integrated model. The findings have practical implications for policy makers and construction practitioners in Iran, similar developing economies and foreign firms planning to operate in Iran.

Collaborative Role of Sociotechnical Components in BIM-Based Construction Networks in Two Hospitals

Building information modeling (BIM)-based construction networks (BbCNs) are teams of specialist organizations working together to execute BIM-related tasks on BIM-enabled projects. Despite the recognized advantages of BbCNs, collaboration among BbCN members remains a serious weakness of BIM-enabled projects. This study compared two highly technologically advanced BIM-enabled hospital projects: one in Norway and one in Australia. Both projects had in common similar technical components, but each settled on a divergent collaborative solution. An extended version of the Leavitt sociotechnical model was used as the theoretical point of departure to inform and interpret the evolution of BbCNs in these two cases. The analysis of the empirical data revealed two emerging collaborative solutions for rectifying misalignment between sociotechnical and technical components of BbCNs during BIM-generated design documentation. The findings confirm that complex projects experience variable numbers of information-sharing participants who depend on and interact with both tangible and intangible knowledge, to varying degrees, over time. Because of these varying interactions, the communication networks on which the project depended must shift to seek realignment among the Leavitt model elements, including actors, tasks, technologies, and systems, within BbCNs. To achieve and maintain effective collaboration within networks, the proactive management intervention of dynamic and evolving requirements and the incorporation of the components of perceptual, attitudinal, and structural influences (PASIs) into BbCNs are of key importance in correcting any misalignments among actors, tasks, and systems.

A qualitative investigation of perceived impacts of virtuality on effectiveness of hybrid construction project teams

Purpose The “virtuality” of a team collaborative interaction is the extent to which it is accomplished in the same place, in fully distributed virtual teams, or in a hybrid combination of the two. However, existence, strength and process of potential association between virtuality and effectiveness in construction project teams have remained elusive. This paper aims to address this gap in the literature. Design/methodology/approach In this study, a conceptual model demonstrating the association between virtuality and effectiveness of teams was developed through integrating the input-process-output (IPO) model and the “Big Five” theory. This conceptual model was contextualised for the construction industry drawing upon conducting 17 semi-structured interviews with hybrid team experts. Findings The findings provide the first model mapping the associations between virtuality and dimensions of team effectiveness for the construction context. Practical implications The discovered patterns of associations between virtuality and dimensions of effectiveness for hybrid construction project teams (HCPTs) will assist managers in designing and running more effective teams. In addition, the findings help construction practitioners better understand how virtuality influence the performance and satisfaction of team members in HCPTs. The present study concludes with outlining a set of recommendations based on the findings of the study. Originality/value As the first study in its kind, the present study offers a new insight into the concept and impacts of virtuality for construction teams and provides instructions and guidelines for designing and maintaining the effectiveness of such teams on construction projects.