Kasun Hewage

Multiple stakeholders in multi-criteria decision-making in the context of Municipal Solid Waste Management: A review

Municipal Solid Waste Management (MSWM) is a complicated process that involves multiple environmental and socio-economic criteria. Decision-makers look for decision support frameworks that can guide in defining alternatives, relevant criteria and their weights, and finding a suitable solution. In addition, decision-making in MSWM problems such as finding proper waste treatment locations or strategies often requires multiple stakeholders such as government, municipalities, industries, experts, and/or general public to get involved. Multi-criteria Decision Analysis (MCDA) is the most popular framework employed in previous studies on MSWM; MCDA methods help multiple stakeholders evaluate the often conflicting criteria, communicate their different preferences, and rank or prioritize MSWM strategies to finally agree on some elements of these strategies and make an applicable decision. This paper reviews and brings together research on the application of MCDA for solving MSWM problems with more focus on the studies that have considered multiple stakeholders and offers solutions for such problems. Results of this study show that AHP is the most common approach in consideration of multiple stakeholders and experts and governments/municipalities are the most common participants in these studies.

‘Socializing’ sustainability: a critical review on current development status of social life cycle impact assessment method

Social life cycle assessment (S-LCA) is a technique to assess the potential social impacts of a product or service caused by its life cycle. The aim of this paper is to critically review the methodologies applied in S-LCIA and establish its current development status by highlighting areas for improvement. The UNEP/SETAC Guidelines published in 2009 provided general procedures for conducting S-LCA, but lack S-LCIA methods. Many new S-LCIA methods have been proposed but these are inherently different, indicating a scientific and well-accepted S-LCIA method is yet to be developed. Broadly, two types of S-LCIA methods, i.e. performance reference point and impact pathways methods are in use. A direction for future research could be the refinement of the social hotspots database and the social hotspot index calculation method. Moreover, the S-LCIA method could be developed by combining the performance reference point and impact pathways methods.

Emergy-based life cycle assessment (Em-LCA) for sustainability appraisal of infrastructure systems: a case study on paved roads

Civil infrastructure systems are critical assets that are subjected to damage, service-life deterioration, and increasing maintenance and rehabilitation cost. Effective infrastructure management and principles of sustainable development can help to find an optimal compromise between economic growth and environmental protection for all stakeholders. Colloquially, sustainability refers to meeting triple-bottom-line (TBL) performance objectives including environmental protection, economic prosperity, and social acceptability and equity as a result of short- and long-term policy decisions. In this paper, a comprehensive framework based on the integration of emergy synthesis and life cycle assessment (LCA) has been investigated for a public infrastructure system. The main purpose of the applied method, emergy-based LCA (Em-LCA), is to facilitate an informed decision making process for different asset management scenarios, by identifying and quantifying the attributes of TBL impacts over the life cycle of a civil infrastructure system. As a case study, Em-LCA framework has been applied to evaluate the sustainability of two different scenarios for a road construction project in interior British Columbia, Canada. The results indicate that Em-LCA offers a good understanding to address sustainability issues in infrastructure systems and provides quantitative and transparent results to facilitate informed decision making for asset management.

Stable strategies analysis based on the utility of Z-number in the evolutionary games

Evolutionary games with the fuzzy set are attracting growing interest. While among previous studies, the role of the reliability of knowledge in such an infrastructure is still virgin and may become a fascinating issue. Z-number is combined with “restriction” and “reliability”, which is an efficient framework to simulate the thinking of human. In this paper, the stable strategies analysis based on the utility of Z-number in the evolutionary games is proposed, which can simulate the procedure of human’s competition and cooperation more authentically and more flexibly. Some numerical examples and an application are used to illustrate the effectiveness of the proposed methodology. Results show that total utility of Z-number can be used as an index to extend the classical evolutionary games into ones linguistic-based, which is applicable in the real applications since the payoff matrix is always determined by the knowledge of human using uncertain information, e.g., (outcome of the next year, about fifty thousand dollars, likely).

Review of Contemporary Construction Procurement Practices

AbstractProcurement is a key process in a construction project that creates and manages contacts. Procurement activities span from identification of requirements to project closeout, making it a perfect mode for integrating organizational strategic directions. Lately, the strategic importance of procurement has been widely acknowledged by academics as well as industry professionals. Construction procurement is a complex process with a large number of available options and directions. Ad hoc statistics show that modern initiatives such as sustainability, life-cycle costing, and standardization are getting integrated with procurement. However, there is no unified view in the construction industry on procurement as a project process. This paper presents a comprehensive review of traditional and emerging procurement practices in the construction industry. The current procurement practices are analyzed by separating into three segments; processes, methods, and policies. Furthermore, strengths and weaknesses of...

A novel solution for construction on-site communication - the information booth

A recent study on construction productivity improvement at the University of Calgary revealed the direct tool time (working time) of Alberta’s commercial construction to be about 51%. This study exposed inadequate communication and unavailability of required information as the main causes for a relatively lower tool time. Use of information technology (IT) to overcome widely visible communication issues was extremely limited at the construction site level. Construction companies’ hesitation to adopt new technologies was well noted whereas construction workers expressed their willingness and ability to use IT at the site level. The objective of this paper is to discuss the concept and the application of a novel communication tool (called an information booth) developed and pilot tested at a construction project. The concept and the technology presented in this paper have been tested at an actual construction project resulting in improvements in construction productivity, worker satisfaction, and efficiency...

Building Information Modeling-Based Analysis to Minimize Waste Rate of Structural Reinforcement

AbstractBuilding information modeling (BIM) is an emerging tool in architecture/engineering/construction (A/E/C) industry that is used to design, document, and enhance communication among all the project stakeholders. Trim loss of rebar can be minimized with the use of discrete bars. To achieve this goal, a model to analyze reinforced concrete structure with one-dimensional (1D) cutting waste-optimization technique, integrated with BIM, is proposed. Building information modeling is selected as the hub in communicating project information among diverse design teams. This process permits project teams to utilize BIM models to simulate architectural and structural design requirements, and compare results speedily to make necessary changes in the designs to minimize rebar waste. The BIM rebar optimization analysis approach also supports cost-effective decision making during the design process. The proposed approach was validated with a two-story reinforced concrete structure, and the results indicated a high ...

AHP based life cycle sustainability assessment (LCSA) framework: a case study of six storey wood frame and concrete frame buildings in Vancouver

Construction and building industry is in dire need for developing sustainability assessment frameworks that can evaluate and integrate related environmental and socioeconomic impacts. This paper discusses an analytic hierarchy process (AHP) based sustainability evaluation framework for mid-rise residential buildings based on a broad range of environmental and socioeconomic criteria. A cradle to grave life cycle assessment technique was applied to identify, classify, and assess triple bottom line (TBL) sustainability performance indicators of buildings. Then, the AHP was applied to aggregate the impacts into a unified sustainability index. The framework is demonstrated through a case study to investigate two six storey structural systems (i.e. concrete and wood) in Vancouver, Canada. The results of this paper show that the environmental performance of a building in Canada, even in regions with milder weather such as Vancouver, is highly dependent on service life energy, rather than structural materials.

An overview of air emission intensities and environmental performance of grey cement manufacturing in Canada

Abstract Air emissions generated in grey cement manufacturing originate primarily from the combustion of fossil fuels required to heat the kiln and the chemical reaction of raw materials in the pyroprocessing phase. Given that the kiln system is enclosed, air emissions generated, discharge from a single point source kiln stack. Unlike other industries, the point source kiln stack enables the cement sector to accurately monitor and record total air emissions. The largest contributors to air emissions from grey cement manufacturing are carbon dioxide (CO2), oxides of nitrogen (NOx), sulphur dioxide (SO2) and dust/particulate matter (PM). In Canada, grey cement manufacturing facilities are required to annually report these emissions through the National Pollutant Release Inventory (NPRI). Since CO2, NOx, SO2 and PM are the largest contributors to air emissions, and Canadian grey cement facilities are required to report these emissions, combining NPRI data with annual grey cement production data allows for the development of intensity-based environmental performance indicators. Based on data provided by NPRI, in combination with industry production, we can better understand the environmental performance of Canada’s grey cement manufacturing. On the global stage, intensity-based performance measures provide a useful tool for comparison and demonstrate a strong environmental performance for grey cement production in Canada. As an energy intensive and trade exposed (EITE) grey cement manufacturing is vulnerable to unbalanced environmental policy, which may ultimately result in leakage of production and air emissions to developing countries.

Generating Z-number based on OWA weights using maximum entropy

In the application of Z‐number, how to generate Z‐number is a significant and open issue. In this paper, we proposed a method of generating Z‐number based on the OWA weights using maximum entropy considering the attitude (preference) of the decision maker. Some numerical examples are used to illustrate the effectiveness of the proposed method. Results show that the attitude (preference) of the decision maker can give an optimal possibility distribution of the reliability for Z‐number using maximum entropy.