This chapter contains sections titled: Value of Design for Manufacturability Deficiencies in Boolean-Based Design Rules in the Subwavelength Regime Impact of Variability on Yield and Performance Industry Challenge: The Disappearing Process Window Mobility Enhancement Techniques: A New Source of Variability Induced by Design–Process Interaction Design Dependency of Chip Surface Topology Newly Exacerbated Narrow Width Effect in Nano-CMOS Nodes Well Proximity Effect Need for Model-Based DFM Solutions Beyond 65 nm Summary References