Liyin Shen

Implementation of environmental management in the Hong Kong construction industry

The control of environmental impacts from construction has become a major issue to the public. Whilst the implementation of environmental management in construction has a direct contribution to environmental protection, it involves allocating a variety of resources for practicing various environmental management methods such as noise control, treatment of polluted water, waste recycling and reusing, and so on. The application of these methods leads to an increase in labour use, materials handling costs, which can limit their implementation. This paper provides a profile of environmental management in Hong Kong construction by identifying what contractors in Hong Kong consider to be the benefits of and barriers to the practice. The appropriateness of measures for mitigating the barrier effects is investigated. The paper provides empirical evidence of the benefits of and barriers to the process of increasing the implementation of environmental management among contractors in Hong Kong. It should help contractors to adjust their environmental management policy by efficient resources allocation within their companies.

Using systems dynamics to better understand change and rework in construction project management systems

The management of construction is complex enough without changes (e.g. to design/specification/client requirements), yet it is a familiar characteristic of in construction projects. To effectively manage change, project managers have to undertake detailed planning; to integrate the work activities of consultants, subcontractors and suppliers. In this context, changes are unplanned disturbances that (typically) interfere with the intended progression of work. Given this interference, what are the consequences of such disturbances on project performance and how can/do/should project managers deal with changes effectively? This paper describes how changes (and their actions or effects otherwise known as dynamics) can impact the project management system. Using a case study and the methodology of systems dynamics, the major factors influencing a projects performance are observed. The need for understanding of how particular dynamics can hinder the performance of a project management system are highlighted.

Key Assessment Indicators for the Sustainability of Infrastructure Projects

Infrastructure projects have major effects on implementing the principles of sustainable development. Infrastructure projects will continue to be developed in the coming years, particularly in developing countries such as China and India; therefore, it is important to find methods and solutions for improving the sustainability of them. Although existing studies have suggested various methods for practicing sustainable development principles in the process of implementing infrastructure projects, effective assessment indicators are unavailable, which presents a barrier to the effective assessment of infrastructure project sustainability. This study introduces key assessment indicators (KAIs) for assessing the sustainability performance of an infrastructure project. The research data used for analysis were collected from a questionnaire survey given to three groups of experts, including government officials, professionals, and clients in the Chinese construction industry. The fuzzy set theory was used to establish KAIs. A procedure for using the KAIs is demonstrated by a case study. These research findings provide an alternative solution to appraise the sustainability of infrastructure projects.

Project risk management in Hong Kong

Abstract This paper identifies what practitioners in Hong Kong consider to be the most serious project delay risks and the effective actions for managing these risks. Practitioners risk management actions and their effectiveness have been investigated through a questionnaire survey. The paper provides an indication of the limited application of various analytical techniques available for risk assessment in the Hong Kong construction industry.

A CHECKLIST FOR ASSESSING SUSTAINABILITY PERFORMANCE OF CONSTRUCTION PROJECTS

Construction sustainability performance is indispensable to the attainment of sustainable development. Various techniques and management skills have previously been developed to help improving sustainable performance from implementing construction projects. However, these techniques seem not being effectively implemented due to the fragmentation and poor coordination among various construction participants. There is a lack of consistency and holistic methods to help participants implementing sustainable construction practice at various stages of project realisation. This paper develops a framework of sustainability performance checklist to help understanding the major factors affecting a project sustainability performance across its life cycle. This framework enables all project parties to assess the project sustainability performance in a consistent and holistic way, thus improving the cooperation among all parties to attain satisfactory project sustainability performance.

A dynamic model for assessing the effects of management strategies on the reduction of construction and demolition waste

During the past few decades, construction and demolition (C&D) waste has received increasing attention from construction practitioners and researchers worldwide. A plethora of research regarding C&D waste management has been published in various academic journals. However, it has been determined that existing studies with respect to C&D waste reduction are mainly carried out from a static perspective, without considering the dynamic and interdependent nature of the whole waste reduction system. This might lead to misunderstanding about the actual effect of implementing any waste reduction strategies. Therefore, this research proposes a model that can serve as a decision support tool for projecting C&D waste reduction in line with the waste management situation of a given construction project, and more importantly, as a platform for simulating effects of various management strategies on C&D waste reduction. The research is conducted using system dynamics methodology, which is a systematic approach that deals with the complexity - interrelationships and dynamics - of any social, economic and managerial system. The dynamic model integrates major variables that affect C&D waste reduction. In this paper, seven causal loop diagrams that can deepen understanding about the feedback relationships underlying C&D waste reduction system are firstly presented. Then a stock-flow diagram is formulated by using software for system dynamics modeling. Finally, a case study is used to illustrate the validation and application of the proposed model. Results of the case study not only built confidence in the model so that it can be used for quantitative analysis, but also assessed and compared the effect of three designed policy scenarios on C&D waste reduction. One major contribution of this study is the development of a dynamic model for evaluating C&D waste reduction strategies under various scenarios, so that best management strategies could be identified before being implemented in practice.

Application of system dynamics for assessment of sustainable performance of construction projects

Sustainable performance is expected to become a major factor when examining the feasibility of a construction project in terms of its life cycle performance. The study on which this paper is based developed a simulation model, using system dynamics methodology, to assess the sustainable performance of projects. Three major factors are used to examine project sustainable performance (PSP): the sustainability of economic development (E), the sustainability of social development (S), and the sustainability of environmental development (En). Sustainable development ability (SDA) was used as a prototype to evaluate the degree of sustainalbe performance. The simulation software ‘ithink’ was used to help with the application of the model to a real life case. This paper explains and demonstrates the procedures used to develop, the model and finally offers an approach for assessing the feasibility of a construction project in terms of its sustainable performance.

Factors constraining the development of professional project management in China's construction industry

Abstract This paper introduces a survey aimed at identifying the underlying factors that constraint the development of professional project management in Chinas construction industry. Professional construction project management, which is known as construction supervision (CS) in China, was introduced into Chinas construction industry in 1988. After more than 10 years of rapid growth, the further development of CS is challenged by a number of arising problems. Based on the findings of the survey, this paper highlights the most significant factors causing these problems. These factors are related not only to CS companies, but also to clients, other construction professionals, and the environment of the construction market. It is anticipated that the discussion of these factors will provide a basis for future strategies to promote the development of CS in China and also provide a useful reference for other developing countries which face similar problems in promoting the applications of professional construction project management in the construction industry.

Emergy analysis of the recycling options for construction and demolition waste

Construction and demolition (C&D) waste is becoming a major contributor to environmental pollution. In Shanghai, China, the quantity of C&D waste is 2.11E+07 t/yr, which accounts for 45% of the total quantity of solid waste. There has been a growing promotion of recycling C&D waste as an effective way to solve this waste problem. However, the evaluation of the efficiency of recycling C&D waste as a potential source of resources is largely based on traditional economic analysis. The economic analysis emphasizes money instead of the harmony between economic benefit and environmental effects. There is a need for a new strategic approach to investigate the efficiency of recycling C&D waste to achieve the integration between economic, social and environmental effects. Emergy theory can be employed to analyze different recycling options for C&D waste. With reference to the Chinese construction industry, this paper demonstrates that the close-loop recycling option is better than the open-loop recycling option for C&D waste in terms of the integration of social, environmental and sustainable aspects. To evaluate different technology solutions for C&D waste recycling, the emergy theory and method is not limited to a cost-benefit balance but can include economic, social, environmental and sustainable effects.

A computer-aided decision support system for assessing a contractor's competitiveness

This paper presents a computer-aided decision support system for assessing a contractors competitiveness. Measures of competitiveness are employed to describe a contractors strengths and weaknesses, thus to assist project clients in identifying proper contractors at the pre-qualification stage. The identification of a contractors weakness can also help the contractor adopt proper measures to improve its competitiveness. Based on a competitiveness scoring model, a Windows-standard Decision Support System Contractors Competitiveness Assessment Scoring System (C-CASS) was developed in this study. Case studies in a simulated environment are used to demonstrate the application of this system.