1. Department of Industrial Engineering and Management, Faculty of Engineering, Lucian Blaga University of Sibiu, 550024 Sibiu, Romania
2. S.C. DSC DIMECOSAB S.R.L., 210233 Târgu Jiu, Romania
3. Faculty of Engineering, Constantin Brancuși University of Târgu Jiu, 210185 Târgu Jiu, Romania