Design Space and Critical Process Parameters (CPPs) are familiar terms but have yet to take on a precise, harmonized meaning in the biopharmaceutical industry. This presentation is an exploration of one company's challenges in identifying CPPs, positioning them in regulatory submissions and understanding the risks and benefits of doing so. The CPP identification process begins during process development where Design of Experiments is used to understand the sensitivity of Critical Quality Attributes to all process parameters over wide ranges. Scale-up and technology transfer require a CPP risk assessment using the principles of Quality Risk Management to prioritize those Process Parameters that require the tightest control. Process validation is then designed to demonstrate the ability to control CPPs in manufacturing. Reduced scale validation studies demonstrate the ability to deliver desired product quality attributes over the allowable CPP ranges. CPP ranges are used to support one proposed definition of a Design Space in global regulatory submissions.