Plastics processing companies are facing ever-increasing international competition. This competition is forcing European companies to drive forward cost disadvantages such as labor and energy costs through innovative and smart technologies and the optimization of processes to enhance efficiency. Process analytical technology offers an essential criterion for the evaluation of product qualities. The evaluation of the product quality during plastics processing directly at or nearby the processing plant enables a significant increase in productivity and reduces the occurrence of rejection rates. In addition, there is a progressive mandatory for complete control of product quality to be able to trace any deviations in production. This requirement of the customers can only be realized by an increasing digitalization of the processes. At the same time, digitalization offers a great opportunity to first integrate fast measurement methods in the form of inline and online procedures into existing processes for product quality control and insurance. In the following subchapters, an overview of the process analytical technologies available is given. Further, the advantages of process digitalization are described and exemplified by the compounding and foaming process. Next the term “digital twin” is introduced and explained by diverse project examples. Finally, the three examples “Dry processing of bead foams,” “RF-process bead molding,” and the “MoPaHyb” project with focus on efficiency enhancement through supervised processes and process chains are presented at the end of this chapter.