Quality by design (QbD) refers to a systematic approach to product development that is based on understanding the requirements of the end-user and designing products that meet these requirements. Key synonyms for QbD include Design Quality, Quality Control, Product Design, and Design for Quality. These terms all refer to the process of designing and evaluating products to ensure that they meet the required quality standards. By focusing on quality from the outset of the design process, QbD helps to minimize the risk of defects and improve the overall quality of the final product. QbD has become increasingly important in industries such as pharmaceuticals and medical devices, where the quality and safety of products are of the utmost importance.