169 research outputs found
Overview of Multi-Objective Optimization Approaches in Construction Project Management
The difficulties that are met in construction projects include budget issues, contractual time constraints, complying with sustainability rating systems, meeting local building codes, and achieving the desired quality level, to name but a few. Construction researchers have proposed and construction practitioners have used optimization strategies to meet various objectives over the years. They started out by optimizing one objective at a time (e.g., minimizing construction cost) while disregarding others. Because the objectives of construction projects often conflict with each other, single-objective optimization does not offer practical solutions as optimizing one objective would often adversely affect the other objectives that are not being optimized. They then experimented with multi-objective optimization. The many multi-objective optimization approaches that they used have their own advantages and drawbacks when used in some scenarios with different sets of objectives. In this chapter, a review is presented of 16 multi-objective optimization approaches used in 55 research studies performed in the construction industry and that were published in the period 2012â2016. The discussion highlights the strengths and weaknesses of these approaches when used in different scenarios
Managerial competencies of female and male managers in the Swedish construction industry
The construction industry is one of the most male dominated industries around the world, not only when it comes to workers, but also as regards managers. Only 5% of the managers in the Swedish construction industry are women. The managerial competencies of individuals working as managers in the Swedish construction industry are researched to get a clearer understanding of the situation, and to investigate if this lack of balance between male and female managers has to do with differences in managerial competence. The management development questionnaire provided by Human Resource Development Press was sent to 143 managers in the Swedish construction industry and 112 respondents (44 women and 68 men) assessed themselves in 20 competencies, resulting in a response rate of 78%. The Mann-Whitney U test showed that female and male managers possess equal managerial competencies in 17 of the 20 competencies. Male managers rated themselves as having better managerial competency than females in two of the 20 competencies, namely âresilienceâ and âdecision makingâ. Female managers rated themselves as having better managerial competency than males in âsensitivityâ, which follows the social norm of what is expected of a woman. It was also found that both groups scored high in decision making, reflecting traditional virtues of construction managers as decisive and active. The most important result is not the differences but the many similarities between women and men working as managers in the construction industry. Thus, it is concluded that female managers are as competent as male managers in the Swedish construction industry
Motivation of civil engineers and architects in Turkey
Motivation is one of the key factors that stimulate individuals to improve their productivity. Therefore, motivation of construction workers has been debated with considerable interest by participants in the construction industry. However, motivating only construction workers, but ignoring the motivation of construction professionals, viz., architects and civil engineers, may not be enough to successfully complete a construction project. Although motivation of construction professionals may also enhance the performance of a construction project, this topic is mostly ignored in the motivation literature. This study attempts to fill this gap by (1) identifying the motivators that are of importance to architects and civil engineers and (2) exploring the statistical difference between architectsâ and civil engineersâ motivators. For this purpose, a questionnaire survey was administered to Turkish architects and civil engineers to collect data on their perceptions of the importance of different motivators. The case of Turkey is investigated because several of the larger Turkish contractors undertake construction projects outside their home country. Statistical analysis was performed on the collected data to verify whether there are statistically significant differences in the perception of some motivators by architects and civil engineers. The study demonstrates the existence of a statistically significant difference between architectsâ and civil engineersâ motivators. Identifying the architectsâ and civil engineersâ motivators may help construction companies in motivating their architects and civil engineers more effectively, thus developing a quality workforce
Desired points at minimum cost in the âOptimize Energy Performanceâ credit of leed certification
This paper presents a method that guides designers in obtaining the desired number of earned points in the âOptimize Energy Performanceâ credit of the âEnergy and Atmosphereâ category of LEED version 4 (v4) certification at minimum cost. The model creates different scenarios, identifies the LEED points and  costs for each scenario. The energy analysis calculations are performed by Sefaira, the quantities of materials are received from Autodesk Revit, and the cost information comes from the RSMeans Database. A macro in Excel automates the process. An office building was used as a case study to illustrate the applicability of the proposed method. The minimum cost necessary to achieve any number of points in the âOptimize Energy Performanceâ credit were calculated, such as a minimum cost of 476,684 for 5 points. The primary contributions of this research include (1) the development of a tool that allows designers to pick the most economical alternative for the desired points in the âOptimize Energy Performanceâ credit, and (2) the first time integrated use of an energy simulation software (Sefaira), a cost database (RSMeans), and a BIM software (Autodesk Revit)
Determinants of transaction costs in construction projects
Transaction costs occur when a good or service is transferred across a technologically separable interface, and include the costs of drafting, negotiating and enforcing an agreement, and also the costs of governance and bonding to secure commitments. In the complex and high risk environment of a construction project, questionable decisions can be made in the planning and design phase, and disagreements, conflicts, disputes, change orders, and claims can occur in the construction phase. These problems contribute to an increase in transaction costs. Transaction costs at the pre-contract phase of a project are different from the transaction costs at the post-contract phase. However, there is no consensus on a standard definition of transaction costs in construction projects. In this study, a detailed literature review focusing on transaction costs in construction project management is presented. The factors that affect transaction costs are identified and categorized under the headings of the ownerâs and contractorâs roles in the transaction, project management efficiency, and the characteristics of the transaction environment
Modeling information flow in the supply chain of structural steel components
 Accessing the required information in the supply chain of structural steel components is critical for minimizÂing costly reworks and delays. This paper identifies the information items generated in the different phases of the supply chain related to structural steel components and formalizes the process of producing and using this information. Precise details about different features of the components (e.g., their geometry and weight, connection details, cutting/bending/ punching requirements, and the type and grade of the material) are set in the various tasks performed in the different phases of the supply chain. Regardless of whether one uses paper-based systems or advanced technologies such as smart tags and radio-frequency identification (RFID), a better understanding is achieved of the processes through which a structural steel component passes. The results of this research can be used to streamline the information flow in the supply chain of structural steel components, regardless of the type of tracking technology used, hence reducing delays and reworks
Negotiating the selling price of hydropower energy using multi-agent systems in BOT
During the feasibility study of BOT (Build-Operate-Transfer) hydropower investments, the selling price of energy is the most critical parameter that impacts the net present value (NPV) estimated by the investors. Investors usually consider the price of energy guaranteed by the government during their feasibility studies which is the worst case scenario. However, it is apparent that negotiations that take place between investor and broker determine the price of energy which is affected by various sources of uncertainty associated with the energy demand and country conditions. The objective of this study was to make a realistic estimate of the investorâs selling price by modeling the negotiation process between investor and broker using a multi-agent system (MAS). Thus, the factors affecting the negotiation process were identified, a negotiation protocol between the parties was set up, negotiation scenarios were determined, and modelled by using a MAS. The model was tested on a hydropower investment in Turkey and generated more realistic results compared to the current practice. Investors and brokers may benefit from this study because it considers the potential changes in the market as well as the negotiating postures of parties under different scenarios
Estimating the profitability of hydropower investments with a case study from Turkey
Energy demand has been increasing, but traditional sources of energy are depletable. New investments are needed in renewable energy production. Hydroelectric power plants are often considered a feasible renewable source of energy and are often organized as a public private partnerships (PPP). However, risk factors stemming from the macro environment as well as project conditions should be considered in performing feasibility studies. The objective of this study was to develop a method that can be used to predict the profitability of hydropower investments considering the relevant risk factors. To that end, a cash flow that represents the construction and operation period is set up, the risk facÂtors involved in such projects are identified, the impacts of these risk factors on the cash flow parameters are assessed, and Monte Carlo simulation is performed to estimate the net present value (NPV) of a hydropower investment. The proposed method was tested in a hydropower investment located in Turkey and generated credible results that could be of great benefit to potential investors operating in similar conditions. The primary contribution of this research is the creation of a method that allows investors to assess the profitability of a hydropower investment by using a stochastic approach
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