The slopes underlain by colluvium are more prone to occurrence of landslides with most destructive natures. Also, the general in situ field tests and laboratory tests fails in true representation of in situ strength characteristics of a colluvium matrix suggesting the use of back analysis to determine mechanical properties. This paper aims to understand the problems faced in colluvial soils and suggest site-specific various methodologies and techniques attempted to overcome challenges. Limit Equilibrium Method (LEM) and Finite Element Method (FEM) analysis are both conducted to evaluate properties of the slope from back analysis. The cohesion variance between FEM and LEM methods for various slope angle during back analysis were analyzed and interpreted based on output of software’s. The crucial variables for understanding the actual problems, designing stable slopes and assessing terrain risks are discussed in this paper. Devising the methods of understanding the problem to constitute a sustainable, realistic and economic design; especially in case of Nepal with dynamic landscapes, can lay a foundation to fill gaps in related uncertainties and challenges.