Modelling and Solving the Project Time-Cost-quality trade off Problem on Condition of the Dependence of Quality on Time and Cost

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 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.

Keywords

• project scheduling
• time
• cost and quality trade-off
• multi-objective programming
• fuzzy goal
• fuzzy decision making