Cathodic protection (CP) is widely used for protection of metallic structures from corrosion. However, an empirical approach during design and the limited coverage of CP monitoring activities can cause nonuniform potential distribution throughout the system which results in the local area vulnerable to corrosion regardless of applied CP. The use of numerical modeling tools based on finite element or boundary element methods can provide reliable and quantitative solutions to predict the CP performance. Numerical approach also supports to analyze the effectiveness of CP system and pinpoint the weak area in the whole system if it is compared with field data. In this paper case studies showing the benefits of numerical analysis to optimize the CP systems is presented, which include a microbiologically influenced corrosion of the underground steel pipeline beneath the disbonded coating and a digital twin approach of pipeline CP network based on a forecast of performance by the combination of numerical modeling and field CP data analysis to fully maximize the benefits of CP is introduced.