This book discusses the relationship between the philosophy of science and philosophy of engineering, and demonstrates how philosophers of engineering design as well as design researchers can benefit from the conceptual toolkit that the philosophy of science has to offer.  In this regard, it employs conceptual tools from the philosophical literature on scientific explanation to address key issues in engineering design and philosophy of engineering design. Specifically, the book focuses on assessing the explanatory value of function ascriptions used in engineering design and philosophy of technical functions; on elaborating the structure of explanation in engineering design; on assessing the role and value of design representations in engineering design and philosophy thereof; and on elaborating means for the testing of design methods. Presenting a novel and effective approach to tackling key issues in the field, philosophers of engineering and design alike will greatly benefit from this book.