The "Drilling and Blasting" (P & V) in tunneling, has been replaced by a variety of types and sizes of tunneling machines (TBMs) for technological progress, productivity demands and environmental control. This study is intended as a framework for selecting the most suitable system of excavation under a minimum length to justify its application. Both the TBM MK 12 and the P & V were studied in the headrace tunnel No. 4 Hydroelectric Project Yuncan. We show that for digging long tunnels, TBM have greater advantages than the P & V, plus the minimum disturbance to the remaining rock, speed of excavation, increased safety for personnel and equipment, lack of gas blasting , minor excavation area, among others.