In this review we describe recent developments in linear and integer (linear) programming. For over 50 years Operational Research practitioners have made use of linear optimisation models to aid decision making and over this period the size of problems that can be solved has increased dramatically, the time required to solve problems has decreased substantially and the flexibility of modelling ...

This paper considers multiobjective linear programming problems (MOLPP) where random fuzzy variables are contained in objective functions and constraints. A new decision making model optimizing possibilistic value at risk (pVaR) is proposed by incorporating the concept of value at risk (VaR) into possibility theory. It is shown that the original MOLPPs involving random fuzzy variables are trans...

cost reduction is one of the methods applied for improving the productivity of organizations. in productivity literature, particularly in nonparametric methods, cost reduction related methods are regarded as input oriented models. this paper presents a supply chain management (scm) model in which purchasing iron ore and coke from different resources, along with production and distribution of st...

this paper presents a genetic algorithm (ga) for solving a generalized model of single-item resource-constrained aggregate production planning (app) with linear cost functions. app belongs to a class of pro-duction planning problems in which there is a single production variable representing the total production of all products. we linearize a linear mixed-integer model of app subject to hiring...

this paper is focused on the tactical design of steel supply chain (ssc). a general mathematical model is proposed to integrate production and transportation planning in multi-commodity ssc. the main purpose is to prepare a countrywide production and distribution plan in an ssc with three layers consisting of iron ore mines as suppliers, steel companies as producers, and subsidiary steel compan...

information on the productivity, costs and applications of the logging system is a key component in the evaluation of management plans for the rehabilitation and utilization of caspian forests. skidding and road construction costs are expensive forest operations. determining the optimum forest road network density is one of the most important factors in sustainable forest management. logging me...

a procedure is presented that synthesizes fractional crystallization separation processes to obtain pure solids from multi-component solutions. the method includes a procedure to generate a network flow model to identify alternative process designs for fractional crystallization. the main advantage of this systematic procedure with respect to other reported procedures is using non-equilibrium s...

many ranking methods have been proposed so far. however, there is yet no method that can always give a satisfactory solution to every situation; some are counterintuitive, not discriminating; some use only the local information of fuzzy values; some produce different ranking for the same situation. for overcoming the above problems, we propose a new method for ranking fuzzy quantities based on ...