Written by twenty-five authors from academia, pharmaceutical industry and Pharmacopeias worldwide, this monograph covers the fundamentals and applications of Quality by Design (QbD) and Analytical Quality by Design (AQbD) in a practical and didactic manner. The book starts by describing the motivation and the urgent need for the implementation of the QbD framework in pharmaceutical development, along with the definition of its major elements: Quality Target Product Profile (QTTP), Critical Quality Attributes (CQAs), Critical Process Parameters (CPPs), Critical Material Attributes (CMAs) and the importance of using multivariate methods of Design of Experiments (DOE). The concept of life cycle and regulatory perspectives are discussed. Three chapters are entirely dedicated to DOE theory from screening to optimization designs. Moreover, a comprehensive discussion on modelling and data treatment is presented. Practical aspects of QbD and DOE for pharmaceutical product and process of different dosage forms is included, as well as a practical guide of the input process variables, material attributes, intermediate, and final quality attributes for the most representative pharmaceutical processes. Analytical Quality by Design (AQbD) is also deeply explored, including risk analysis, definitions of Analytical Target Profile (ATP), Method Operable Design Region (MODR) and the life cycle approach, taking into account the compendial and regulatory perspectives. A detailed example of a new chromatographic method for the quality control of a pharmaceutical topical product based on the AQbD procedure is shown. Finally, advanced statistical approaches and DOE methods for extraction studies of bioactive compounds are also presented. The vast amount of information offered in this book provides a comprehensive perspective on QbD, AQbD and DOE principles, essential tools for modern pharmaceutical and analytical development.