This work presents an analysis of Magnetic Flux Leakage (MFL) signal to better understand the forward problem and the physics contributing to the nature of the signals. The analysis of the MFL signal was done through the implementation of two mathematical models such as the Magnetic Dipole Model (MDM) and Finite Element Method (FEM). This thesis shows that MFL signals presents a similar behavior even if the defect's characteristics differ (length, shape and depth). Also, this thesis introduces a Wavelet Analysis (WA) as a tool for further characterization of the MFL signal. This study presents how WA can identify and expose specific characteristics of each defect's MFL signal, even though the signals of different defect shapes were very similar to each other. The main advantage of this work is that it can achieve without changing the current MFL technique, additional information of the defect can be extracted.