Concept of mass is one of the most complicated concepts in physics. Philosophically, the mass can be defined in three different ways and according to these definitions; there are three different kinds of masses. These are named as the active gravitational mass, passive gravitational mass and the inertial mass. Several experiments have been performed to distinguish these masses, and in all these experiments, surprisingly these masses come out to be the same. Therefore, even though conceptually these masses are different but they are considered to be same empirically. Hence, in modern physics, all these different concepts are abolished and people treat all the three masses as the same. However, in this paper the inertial mass is considered to be different from the other ones. It is thought that the inertial mass of a particle is not completely its intrinsic property and it depends on the position of the particle in the universe, or the background of the position where the particle is located. But the background of a particle keeps on fluctuating randomly due to different types of phenomenon occurring in the universe. Therefore, the exact position or the mass of a particle can not be determined at any time, without knowing the exact positions and the states of all the other particles in the universe. Hence, in this paper, the dynamics of a particle has been defined statistically, which leads to the Schrodinger equation. The mathematical formalism presented in this paper can explain the quantum mechanical phenomenon completely classically and thus it gives quantum mechanics a sense of completeness.