The process to identify and describe target markets can be challenging for marketers due to the complexity of B2B markets and industrial products. This case-based study aims to bridge the gap between theory and praxis by developing a process to determine target markets for Siemens SIMATIC controllers, which are highly technological products designed for process control and used in industrial applications. The author conducted a literature review to investigate the current understanding of B2B market segmentation and target marketing and collected qualitative data from Siemens. This study defines segmentation variables leveraging segmentation models as a foundation to build and describe customer clusters. Next, target markets for SIMATIC controllers, focused on redundant systems, are selected and mapped. On that basis, the author derives a process for reviewing and defining target markets for the existing controller portfolio and future product launches.