Abbas Shoul; Esmaeil Keshavarz
Abstract
In the present research, Time-Cost-Quality trade off problem is formulated and solved, from a new point of view. To this end, quality is defined as a function of time and cost, then by defining the project’s quality as minimum value of quality of activities and regarding predecessor relations between ...
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In the present research, Time-Cost-Quality trade off problem is formulated and solved, from a new point of view. To this end, quality is defined as a function of time and cost, then by defining the project’s quality as minimum value of quality of activities and regarding predecessor relations between activities, a tri-objective programming model is formulated to trade off the time, cost and quality. In order to solve the problem, objective functions of time and cost described as fuzzy goals and a fuzzy decision-making methodology has been used to reformulate the proposed tri-objective model to a single-objective model. Producing a final solution, instead of a set of Pareto efficient solutions, is one of the advantages of proposed method, which prevents decision maker from confusion. In order to describe performance and show the potential applicability of proposed methodology, a time-cost-quality trade-off problem for a project with real data from Organization for Renovating, Developing and Equipping Schools of Kerman province is solved. Finally, in order to validate the proposed model and method, a parametric analysis, which systematically varies the main parameters of model, is employed.
Hamidreza Shahabifard; Behrouz Afshar-nadjafi
Abstract
In this paper, a mathematical model is proposed for project portfolioselection and resource availability cost problem to scheduling activities inorder to maximize net present value of the selected projects preservingprecedence and resource constraints. Since the developed model belongs toNP-hard problems ...
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In this paper, a mathematical model is proposed for project portfolioselection and resource availability cost problem to scheduling activities inorder to maximize net present value of the selected projects preservingprecedence and resource constraints. Since the developed model belongs toNP-hard problems list, so a genetic based meta-heuristic algorithm isproposed to tackle the developed model. In the proposed algorithm besidecommon operators of genetic algorithms such as crossover & mutation, someintelligent operators are utilized for local search in computed resources andshifting the activities with negative cash flows. The key parameters of thealgorithm are calibrated using Taguchi method to accelerate convergence ofthe proposed algorithm. Then, the algorithm is used to solve 90 testproblems consisting 30 small-scale, 30 middle-scale and 30 large scaleproblems to examine the algorithm’s performance. It is observed that, insmall problems, the obtained solutions from the proposed genetic algorithmhave been comparably better than the local optimum solutions stemmedfrom Lingo software. On the other hand, for the middle and large sizeproblems which there is no local optimum available within the limited CPUtime, robustness of the proposed algorithm is appropriate
Abolfazl Kazemi; Pasha Pasha Fakhori; Ali Shakourloo,
Volume 13, Issue 38 , October 2015, , Pages 41-69
Abstract
Accurate scheduling of project is one of the main fundamentals and essential success factors of the project management and also accordance of planning and implementation is considered as the main subject of project management. In this paper, it is tried to propose a practical and suitable system in order ...
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Accurate scheduling of project is one of the main fundamentals and essential success factors of the project management and also accordance of planning and implementation is considered as the main subject of project management. In this paper, it is tried to propose a practical and suitable system in order to schedule various projects more accurately. Currently Program Evaluation and Review Technique (PERT) is used extensively for management of large- scaled projects. In traditional methods of PERT technique, implementation time of each activity is obtained in the form of definite figures or through Beta Distribution but in the real world; it is very hard to estimate the practical implementation time of each activity in an accurate way. By using fuzzy logic in order to overcome the problems related to uncertainty, fuzzy expert system is designed which many limitations and factors affecting the project completion time have been considered in this article. In this regard, output and input parameters of the system have been acquired by questionnaire and validation of the results has been analyzed. The obtained results indicate high power of the system in controlling different situations affecting the project completion time.
