چکیده:
The paper discusses the location-allocation model for logistic networks and distribution centers through considering uncertain parameters. In real-world cases, demands and transshipment costs change over the period of the time. This may lead to large cost deviation in total cost. Scenario based robust optimization approaches are proposed where occurrence probability of each scenario is not known. It is supposed that in this case there would be budget constraints and also holding the products in the distribution centers until sending them to the retailers’ destinations results additive cost that can be defined as inventory control cost in the model. In this paper, uncertainty is defined by different scenarios. Some robust approaches are presented that can be applied in location-allocation problem. The robust scenario based approaches like absolute robust and robust deviation are applied in location- allocation problem. Also a new robust approach is proposed that outperforms the existing classical approaches. The mean expected model has been discussed and compared to the robust proposed approaches. A numerical example illustrates the proposed model and the results have been reported. Finally the com parison of results shows the efficiency of proposed robust approach in comparison of classical approaches and also mean expected model
خلاصه ماشینی:
, 1 (4), 199-210, Autumn 2011 © IAU A Robust Scenario Based Approach in an Uncertain Condition Applied to Location-Allocation Distribution Centers Problem 1*M.
It is supposed that in this case there would be budget constraints and also holding the products in the distribution centers until sending them to the retailers’ destinations results additive cost that can be defined as inventory control cost in the model.
To model robust location-allocation problem with uncertain data, we use a robust scenario based min-max (absolute robustness) optimization approach and also robust min- max regret (robust deviation) approach and also novel robust approach which is limited min-max regret approach which is presented in following section.
Ro bu s t De v i a t i o n ( mi n - ma x r e g r e t ) Also another possible objective function for robust location-allocation model is robust deviation or min- max regret approach that can be written as follows: Minimize Z = Max {(Z – Z *), … , (Z – Z *), … , (Z – Z *)} robust approaches exist in the literature are defined and then proposed as follows: 1 1 a a a∈sets of scenarios p p (2) R o b u st A p p r oa ch es Un certainty in th e parameters of a location- allocation problem including cost parameters and demands is very common.
jkt : denotes the transmission cost of product t P from The robust scenario based limited min-max regret model Distribution center node j Q to retailer node k R.