ABSTRACT
This chapter presents different types of multi-objective decision-making methods, namely, the traditional time-cost trade-off problem, fuzzy linear programming, goal programming and an integer programming problem. Linear programming is a powerful tool used by managers to obtain optimal solutions to problems that involve restrictions or limitations, such as available resources, budgets, and time. In recent years many researchers have combined fuzzy set theory with Program Evaluation and Review Technique (PERT) to handle time estimates in project planning and control problems. The main advantages of methodologies based on fuzzy theory are that they do not require prior predictable regularities or posterior frequency distributions, and they can deal with imprecise input information containing feelings and emotions quantified based on decision-makers subjective judgment. The main difference between linear programming and integer programming models is that linear programming models allow fractional values for the decision variables, whereas integer programming models allow only integer values for integer-constrained decision variables.
