International Journal of Applied Operational Research

en Robust multi-objective economic-statistical design of nonlinear profile monitoring under parameter uncertainty and multiple assignable causes: An MOGWO-based approach عمومى General پژوهشي Research Monitoring nonlinear quality profiles becomes difficult when profile coefficients are correlated, several assignable causes may occur, and process and cost parameters are uncertain. This study develops a robust multi-objective economic-statistical design that integrates a third-order polynomial profile, an EWMA-Hotelling T² monitoring scheme, cause-specific competing risks, scenario-based parameter uncertainty, and a simulation-based regenerative cost model. The decision variables are sample size, sampling interval, control-limit multiplier, and EWMA smoothing parameter. Monte Carlo simulation is used to estimate in-control and out-of-control run-length behavior and calendar-time detection delay, while a constrained mixed-variable multi-objective grey wolf optimizer constructs feasible Pareto alternatives. The proposed search procedure is evaluated descriptively against NSGA-II and MOPSO under a matched verification setting. The results indicate that MOGWO provides a competitive balance between Pareto-front convergence and coverage, although competing algorithms retain advantages on individual diversity measures. Policy-level and sensitivity analyses further show that detection performance and economic cost are strongly influenced by process dispersion, shift magnitude, and out-of-control losses. The proposed framework provides practitioners with a transparent set of monitoring policies for balancing cost, false-alarm protection, detection speed, and robustness under uncertain operating conditions.   Economic-Statistical Design, Statistical Process Control, EWMA-Hotelling T², Multi-Objective Grey Wolf Optimizer (MOGWO), Nonlinear Profile Monitoring, Parameter Uncertainty. 1 25 http://ijorlu.lahijan.iau.ir/browse.php?a_code=A-10-643-1&slc_lang=en&sid=1 H. Majdzangeneh hanieh.mzangeneh@gmail.com 10031947532846002906 10031947532846002906 No Department of Industrial Engineering, CT.C., Islamic Azad University, Tehran, Iran M. J. Ershadi ershadi@irandoc.ac.ir 10031947532846002907 10031947532846002907 Yes Iranian Research Institute for Information Science and Technology (IranDoc), Tehran, Iran M. R. Nabatchian moh.nabatchian@iauctb.ac.ir 10031947532846002908 10031947532846002908 No Department of Industrial Engineering, CT.C., Islamic Azad University, Tehran, Iran