This lecture covers the importance of Design for Testability (DFT) in VLSI systems, focusing on techniques to detect faults, reduce testing complexity, and improve test access. It discusses ad-hoc DFT methods, structured DFT approaches, scan design, scan operating modes, and scan layout procedures. The presentation also includes insights on multiple scan and partial scan techniques, as well as the evolution of testing methods from traditional bed of nails to modern JTAG standards.