Recently developed simple approach for the exact/approximate solution of Schrödinger equations with constant/position-dependent mass, in which the potential is considered as in the perturbation theory, is shown to be equivalent to the one leading to the construction of exactly solvable potentials via the solution of second-order differential equations in terms of known special functions. The formalism in the former solves difficulties encountered in the latter in revealing the corrections explicitly to the unperturbed piece of the solutions whereas the other obviate cumbersome procedures used in the calculations of the former.Using the spirit of prescriptions used for the usual treatments in supersymmetric quantum theory [1], a simple alternative approach has been recently developed [2] to perturbation theory in one-dimensional non-relativistic quantum mechanics. The formulae proposed in this work for the energy shifts and wave functions do not involve tedious calculations, unlike the standard perturbation theory, where it has been clearly shown that the supersymmetric perturbation techniques [3] and other approaches [4] based logarithmic perturbation theory [5] are involved within the more general framework of this novel formalism [2]. Further, this procedure has been used for the exact treatments of quantum states with non-zero angular momentum in case effective potentials have an analytical solution [6], for investigation of perturbed Coulomb interactions [7] and for a systematic search of exactly solvable non-central potentials [8]. The model is later extended to the scattering domain [9] deriving explicitly the changes in the partial wave phase shifts. Successful applications of the model to anharmonic oscillators and Yukawa type potentials are presented in [10] and [11], respectively . With the confidence gained from such applications involving constant mass, the model underlined is employed for the investigation of effective Hamiltonians with spatially varying mass in one-dimension [12] and higher dimensions [13] leading to explicit expressions for the energy eigenvalues and eigenfunctions. These investigations have clarified the relation between exact solvability of the effective mass Hamiltonians in the literature and ordering ambiguity put forward due to the use of a position-dependent mass in equations. The