Knapsack problem in fuzzy nature: Different models based on credibility ranking method

This paper deals with knapsack problem in fuzzy nature, where both the objective function and constraints are considered to be fuzzy. Three different models for proposed including, expected value model, chance-constrained dependent-chance model. Credibility ranking method is applied convert into a crisp equivalent linear one considering triangular trapezoidal numbers. The solution of obtained respect satisfaction degrees constraints. Several numerical examples given demonstrate concepts. approaches model solve pre-disaster investment decision problem.