In recent years, many chemical companies have adopted the concept of sustainable development as a core business value. In this context and with focus on early phases, we present a novel design framework that comprises four stages of process modeling and multiobjective evaluation considering monetary and nonmonetary aspects. Each stage is characterized by the available information as a basis for process modeling and assessment. Appropriate modeling approaches, and evaluation indicators for economy, life-cycle environmental impacts, environment, health, and safety (EHS) hazard, and technical aspects are selected for each defined stage. The proposed framework is demonstrated on the design of a methyl methacrylate (MMA) process: considering 17 synthesis routes, the framework is mimicked step-by-step, to select the route with the best multiobjective performances, and to produce an optimized process flowsheet. As a validation of the framework, evaluation profile of six routes over all stages are compared, and crucial points are identified that should be estimated considerably well in early stages of the framework. (c) 2008 American Institute of Chemical Engineers.