Abstract: Recent advances in technology and fundamental changes in most scientific areas have affected projects and made their nature and environmental circumstances much more complex than in the past. In such conditions, the customary principles and practices of project management are not anymore able to handle the emerging complexities of projects. Fortunately, in recent years, researchers and practitioners have recognized the importance of complexity and tried to identify the various aspects of project complexity and provide appropriate solutions to deal with them. One of the main steps to manage system complexity is to evaluate and measure it. Because of the ambiguity…and uncertainty of complexity context and the difficulty of its exact quantification based on available information, the application of fuzziness could be very appropriate. Hence, in this paper we tried to design and implement an inference system in fuzzy environment to evaluate project complexity. Also, because of the importance of construction projects, we particularly study this kind of projects. Finally, it should be noted that system complexity can exist in two forms: static and dynamic. Therefore, considering the breadth of issues related to each of these two complexity areas, just the static complexity of construction projects has been studied here.
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Keywords: Project management, construction industry, static complexity, evaluation, fuzzy set theory, inference system
Abstract: Time–cost trade-off problems (TCT) are well-known in project management contents. This approach normally applied for scheduling of a project especially where the project should be completed under pre-determined deadline. This paper aims to extend time-cost trade-off (TCT) problems in order to provide a well-organized mechanism for both scheduling and rescheduling processes of a project. The proposed mechanism includes project scheduling which concerns with the TCT problem, monitoring of project performance during execution phase using earned value management (EVM), and also predicting project future performance through statistical modeling. Once the predicted values of project performance indicate the necessity for rescheduling, the…initial TCT problem is modified to determine a new mode for the execution of the project. In the proposed model, also several options have been considered with specific time and cost for an individual activity where options indicate different execution methods (EM) for the implementation of the whole project. Furthermore, due to vagueness and impreciseness associated with data of real case projects, the time and cost behavior of each option presumed as fuzzy numbers. The proposed control mechanism can help project managers to take the advantage of a comprehensive model to schedule, control, and reschedule a project through the life cycle. An illustrative case is then presented to successfully demonstrate the application of the proposed approach.
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Abstract: In project management context, the Earned Value Management (EVM) is a well-known technique. Despite its popularity, the standard EVM suffers from the absence of some features that require being focused further on to make this method more efficient. This paper is addressing such features specifically the financial aspects of cost control system. These aspects that have been absent in the standard EVM include the time value of money, delay in client payment and contractor cash flow in uncertain environment. The proposed model here utilizes fuzzy sets to deal with the uncertain conditions of real projects. It attempts to extend the…theoretical framework of EVM to evaluate and control the financial performance of project and provide a new estimation of project total cost in presence of uncertainty. Finally, 6 case studies are presented to demonstrate how the proposed model can be implemented in real case projects.
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Keywords: Earned value management, fuzzy sets, contractor cash flow, delay in client payment, project management
Abstract: Project managers normally investigate how to reduce the total completion time of projects undertaken subject to the pre-determined objectives. The purpose of this paper is compression of total projects’ duration subject to influencing factors such as cost, time, quality and risk. In the present study, by considering factors affecting project success such as cost, time, quality and risk, project crashing and fast tracking are both employed then a fuzzy multi-objective non-linear model is proposed. Each project is associated with uncertainty and the lack of consideration of these uncertainties might lead to project failure. In addition, a fuzzy approach has been…employed for incorporating the uncertainties associated with activities. In the proposed model, crashing and fast tracking of projects were considered simultaneously for the first time. According to a real case study considered in this paper, after using the proposed model, the cost of compression is also reduced. In addition, we determined which activities have to be crashed or fast tracked in order to attain the objective. The proposed methodology can be practically applied through mega projects such as construction and “Engineering, Procurement, and Construction” (EPC) projects where the deadline closes to being achieved. As another contribution, a unique feature of the proposed model is its capability for taking both crashing and fast-tracking simultaneously into consideration.
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Keywords: Fuzzy multi-objective model, project crashing, fast tracking, time, cost
Abstract: Earned Value Management (EVM) is a well-known project management technique to measure project performance and progress in a significant manner. The EVM has an ability to simultaneously and actively monitor and manage scope, schedule, and cost status via an integrated system. In this paper, firstly, we have formulated EVM in vagueness environment using L-R fuzzy numbers. It improves applicability of the EVM under real-life and uncertain conditions and leads to better planning and taking more appropriate managerial decisions. Also, it overcomes the typical fuzzy numbers' drawbacks. Besides, an efficient approach to calculate estimate at completion (EAC) has been developed. Finally,…an illustrative case proves successful implementation of the proposed method in reality.
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Abstract: Obviously, financial aspect is the most important pillar of technology development. Furthermore, the role of venture capital in developing small and medium size knowledge-based institutions is vital. However, startup portfolio selection and venture capital firms’ syndication have always been critical challenges in VC industry and the need for integrated methods based on sophisticated quantitative techniques are always being felt. In this research, startup portfolio optimization is simulated which is more similar to real world problems rather than other research. In order to attain this goal, preferences of startups as decision-makers and the interaction between investees and investors are considered. Concerning…the complexity of the problem, the best-known model to simulate this problem is an agent-based modeling and also by using harmony search algorithm, the optimization procedure is successfully implemented. Through implementing this procedure, not only the portfolio’s return on investment is optimized but also venture capital firms’ syndication and their share is then determined. Finally, several numerical illustrations are solved using the proposed combinatorial model.
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Abstract: Earned value management is well-known as the most efficient method of project monitoring and control providing relatively reliable information about the project performance. However, this method requires accurate estimates of the progress of project activities, which are always associated with uncertainties that, if ignored or not addressed well, lead to incorrect results. To address this issue, the application of multi-valued logic, in particular fuzzy logic, in earned value management has recently attracted a lot of attention both in practice and research. This paper introduces directed earned value management (DEVM) in which ordered fuzzy numbers are used to express the so-called…uncertainties as well as to capture more information about the trend of the project progress. To evaluate the performance of the proposed method, several numerical examples and a case study are presented. The results reveal that compared to the existing methods, DEVM has a lower computational complexity. Also, it doesn’t suffer from the overestimation effect and as a result, it has a higher ability to express project-specific dynamics. In sum, the proposed method allows project managers to make informed decisions that lead to taking preventive and corrective actions promptly and at a lower cost.
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Keywords: Earned value management, fuzzy earned value management, fuzzy performance indicators, ordered fuzzy numbers, directed earned value management