Electronic packaging constitutes the final and highly critical procedure of the industrial manufacturing process for electronic devices. This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book introduces the structural and material aspects of electronic packaging systems. It presents a wide range of sampling strategies used to quantify uncertainty and propagate randomness through computational models. The book also introduces the fundamental concepts and numerical techniques related to stochastic processes and random fields, which are essential for constructing stochastic finite element models. It focuses on the core of probabilistic structural analysis, presenting both classical and advanced methods for reliability assessment. The book integrates uncertainty modeling with nonlinear finite element analysis. It investigates the impact of geometrical parameters on the reliability of ball grid arrays (BGAs) structures in flip chip packaging using finite element models of individual solder balls and four representative BGA configurations.