On April 2010, the first complete draft of new Model Code 2010 was published. It introduced a number of innovative design approaches, some of them with respect to shear and punching shear. Contrary to Model Code 90 (or some national and international codes such as ACI 318-08, EC-2 or EHE-08), the new Model Code 2010 grounds such design approaches on physical models rather than on empirical formulas. This paper gives an overview of the methodology proposed for punching shear, which is based on the critical shear crack theory. The fundamentals of this theory are explained and justified as well as the application of the theory to the design and assessment of flat slabs. The paper also introduces the design of structures following a levels-of-approximation approach and how can this be applied to punching shear design.