This book captures mainly contents related to system modelling and simulation. It is intended for beginners who have little or no knowledge in system modelling and simulation. It is also suitable for intermediate system analysts and modellers who already have some knowledge of system analysis, modelling and simulation. This text is suitable mainly for university undergraduates, especially those in the area of Engineering, Computer Science, IT and Telecommunication. It starts with what systems are all about, system models and simulation. So whether you are a beginner or an intermediate system modeller, this book will help you master the essentials of inclusive contents more quickly. The book is written in a simple, easy-to-read style, containing numerous examples to illustrate the modelling and simulation concepts used herein. It also contains examples to simplify reader's grasp of the material discussed in each chapter.