The manufacturing industry is challenged by increasing costs of scarce resources, rapid change, and tight competition in global markets, and the need for efficient and sustainable process design and operating strategies. Addressing these challenges has been the focus of process intensification (PI). Polymerization processes face the additional challenge of meeting tight product specifications, which are dictated by the demands of high quality and advanced materials. Meeting these specifications requires the incorporation of complex molecular weight distribution (MWD) models based on population balances of all the polymer chains. Addressing these challenges through process intensification requires the development and application of efficient, robust, and powerful optimization strategies and modeling frameworks, leading to an essential strategy for process intensification of polymerization systems. This survey presents the development and application of novel optimization strategies for model development, process synthesis and design, and the operation of polymer processes. The effectiveness of these optimization-based approaches will be demonstrated on a slurry process for high density polyethylene (HDPE), where significant advances in process intensification have been realized. Future directions are given, with the aim of benefiting both research and application in this field.