Findari, Widya Setia, and Yohanes Anton Nugroho. “Design Improvement of Queuing System Using Simulation and Six Sigma: A Case Study”. International Journal of Applied Business and Information Systems 3, no. 1 (March 1, 2019): 1–8. Accessed April 28, 2024. https://pubs.ascee.org/index.php/ijabis/article/view/156.