Mathematical Problems in Engineering has retracted the article titled “Combined Location-Inventory Optimization of Deteriorating Products Supply Chain Based on CQMIP under Stochastic Environment” published in Mathematical Problems in Engineering in 2018 [1]. The article was found to contain significant material from another article titled “A Conic Integer Programming Approach to Stochastic Joint Location-Inventory Problems” published in Operations Research in 2012 by different authors [2], which was not cited.
Several parts are copied word by word from the other article [2]. In addition, Figure 2 in [1] is similar to Figure 1 in [2], while the results in Figures 3, 4, and 5 in [1] appear to be the same as Figures 2, 3, and 4, respectively, in [2]. Moreover, there are close similarities in the equations and tables. Finally, the results in the Table 1 in [1] and Table 3 in [2] are very closely correlated, despite supposedly not using the same model.
The Mathematical Problems in Engineering authors clarified that their article is different from the other one as they designed a combined location-inventory model for deteriorating products under capacitated facilities, stochastic lead time, multiple products, and correlated retailers’ stochastic demands assumptions. Mathematical Problems in Engineering asked the authors to provide evidence that they conducted these simulations, e.g., code and raw outputs. The authors said the data are already included in the article and no additional data can be provided, and they provided code.
The Editorial Board found that the code and equations provided by the authors did not help determine whether the results are original. Accordingly, we asked their institutions to formally investigate.