Flare management challenges are related to the flaring uncertainty during abnormal situations. In this work, a multi-objective optimization framework is upgraded with multi-period optimization and Monte Carlo simulation to incorporate the risk associated with uncertain flare events. An ethylene plant is used to present the developed framework. Using the ethylene process historical flaring data, Monte Carlo simulation generates probabilistic values for flaring events and event duration. Here, cogeneration unit (COGEN) is considered as the flare reduction alternative. The results of the formulations are presented as a set of Pareto fronts providing insights into the competing techno-economic and environmental objectives. Sensitivity analysis on the factors for the case suggests that some factors such as CO2 tax savings are severely affected by minor variations in flaring profiles, whereas others such as the fixed and operating costs are less sensitive. Hence, using this approach, the decision maker gains techno-economicenvironmental insights regarding the flare reduction alternative (COGEN). (C) 2018 Elsevier Ltd. All rights reserved.