فهرست مطالب محمد افضلی نژاد

The paper addresses the star network structures with centralized management and provides models for evaluating the performance of such structures. Despite the wide range of applications and importance, such structures have not been studied in data envelopment analysis before.

The Data Envelopment Analysis (DEA) method is used for modeling the problem, and a two-level method for efficiency evaluation is proposed.

The proposed models are developed in both multiplicative and envelopment forms. The required formulas for efficiency decomposition and benchmarking are provided. Some results are proved by mathematical discussions and numerical experimentation.

Originality/Value: 

The star structure is seen in many real-world applications. A new method for modelling and evaluation of such structures is introduced and established. The proposed technique, discussions and analytical examinations have a significant contribution to the field of data envelopment analysis and its applications.

Many production processes have a two-stage structure in which production takes place through two stages with separate inputs and outputs for each stage. In these production systems, some outputs of the first stage form inputs for the second stage. These factors are called intermediate data. Since in many practical situations, data is not deterministic and is given in interval form, the efficiency evaluation under interval data is very important. In this paper, some data envelopment analysis models are proposed to evaluate the performance of two-stage systems with interval data and Stackelberg game tradeoff between the stages. By exploiting the mathematical properties of the models, some simplifications are provided to determine the interval efficiency of each stage. For optimistic and pessimistic scenarios, it is shown that the upper and lower bounds of efficiency scores are obtain at the upper/lower bounds of all data except the intermediate data. Using a numerical example, the application of the model and analysis of the results are described.