This book includes eleven excellent chapters that have been prepared using state-of-art methodologies by professional researchers from ten different countries. The chapters in the book comprise the following titles: System Diagnostics and Prognostics: A Review; Random Vibro-Impact Vibration in Mechanical Systems, The Machine for Cutting Cane and Other Aquatic Plants in Navigable Waterways by Agustín de Betancourt y Molina: Analysis by Computer-Aided Engineering Techniques with an Autodesk Inventor Professional; Mechanical Systems and Microfluidics: The Application of a Vision System in the Testing of Fluids Behavior; The Study of Limited Invariant Sets and Structures of Relay Stabilized Systems; Finding an Unbiased Warranty Length for a Product Under Parametric Uncertainty of Underlying Lifetime Models; Modeling of Mechanical Aspects’ (Static, Dynamic) Influence on the Production of Electric Fuel Cell (PEMFC) Power; Quantum Graph-Type Models of the Helmholtz Resonator and Completeness of Resonance States; Applied Research in Forensic Engineering; Energy Efficiency via a Turbulator; and A Mathematical Model of a Rocket Engine for Reliability Analysis.