Contractor selection using the analytic network process

Contractor selection is one of the main activities of clients. Without a proper and accurate method for selecting the most appropriate contractor, the performance of the project will be affected. The multi‐criteria decision‐making (MCDM) is suggested to be a viable method for contractor selection. The analytic hierarchy process (AHP) has been used as a tool for MCDM. However, AHP can only be employed in hierarchical decision models. For complicated decision problems, the analytic network process (ANP) is highly recommended since ANP allows interdependent influences specified in the model. An example is demonstrated to illustrate how this method is conducted, including the formation of supermatrix and the limit matrix.     

A methodology for predicting the severity of environmental impacts related to the construction process of residential buildings

This paper introduces a systematic approach for dealing with potential adverse environmental impacts at the pre-construction stage. The proposed methodology serves as an assessment tool for construction projects to measure the environmental performance of their construction activities. It also provides a consistent basis for comparisons and for future eco-labelling and environmental benchmarking among construction companies and construction sites. Within the methodological framework, nine categories of environmental aspects are proposed: atmospheric emissions; water emissions; waste generation; soil alteration; resource consumption; local issues; transport issues; effects on biodiversity; and incidents, accidents and potential emergency situations. The methodology includes 20 performance indicators developed with the help of a panel of experts. In order to avoid a typical shortcoming in environmental assessments methods, these environmental indicators, both direct and indirect, are always based on quantitative data available in the project documents. Significance limits for environmental aspects are also developed based on a statistical analysis of 55 new-start construction projects. Four case studies are provided to illustrate the practical use of the proposed methodology.     

Reducing the environmental impacts of reverse osmosis desalination by using brackish groundwater resources

The aim of the present work is to find out whether or not, and to what extent, the environmental impacts of reverse osmosis desalination are reduced when brackish groundwater is used instead of sea water. In order to answer this question, the Life-Cycle Assessment (LCA) methodology is used, and two water production plants are compared. The brackish groundwater scenario is based on a plant located in Almería (southern Spain), while the sea water scenario is based on literature data. Four impact categories and two environmental indicators, one of them related to brine discharge, are included. The results show that the key life-cycle issue of brackish groundwater desalination is electricity consumption, and since this is substantially reduced with regard to using sea water, the life-cycle impacts are found to be almost 50% lower. An uncertainty analysis based on Monte-Carlo simulation shows that these environmental savings are significant for all impact categories. Potential local impacts provoked by brine discharge are also found to be lower, due to a reduced content of salts. It is concluded that, when and wherever possible, exploitation of brackish groundwater resources should be assigned priority to sea water resources as an input for reverse osmosis desalination, although it must be taken into account that groundwater, as opposed to sea water, is a limited resource.     

Optimal selection of location for Taiwanese hospitals to ensure a competitive advantage by using the analytic hierarchy process and sensitivity analysis

Implementation of the National Health Insurance scheme in Taiwan since 1995 has intensified competition in the local medical sector. Given elevated living standards island wide, Taiwanese residents have become more health conscious and attach increasing importance to quality healthcare, explaining the heightened consumer demand in the quality and scope of medical services. Additionally, the medical service sector has improved its organizational structure and encouraged hospitals to establish management practices that would increase their competitiveness. In such an intensely competitive environment, selecting the optimal location of hospitals to be established is of priority concern. Therefore, this work presents an analytic hierarchy process (AHP)-based evaluation model. Sensitivity analysis is performed in detail by varying the objective factor decision weight, the priority weight of subjective factors and the gain factors. Adopted herein is the renowned diamond model introduced in Porter's The Competitive Advantage of Nations (1990) that influences how competitive advantages, especially with respect to developing and evaluating the objectives of optimal location selection, are related in order to devise a standardized operational procedure. Besides a literature review and interviews with experts, this study also adopts the modified Delphi method, the AHP and the sensitivity analysis to develop an evaluation method for selecting the optimal location of a regional hospital in Taiwan to determine its effectiveness. The proposed evaluation criterion provides a valuable reference for hospital administrators and academics in establishing a standardized means of selecting the optimal location for new medical care facilities.