Siddarth,
Are you asking what statistical tools should be part of a stability study?
The stability program should cover statistical analysis, and including
Qualitative stability data, and those attributes tested annually or those with an insufficient amount of data. Data should be evaluated for conformance to specifications and the significant change criteria as described in ICH Q1A(R2) (Stability Testing of New Drug Substances and Products) and ICH Q1E, as applicable to the product/material.Start with analyzing for linear data. In the case of non-linear data you need a statistician. In these cases, techniques used to analyze the data should always been explained and justified.
I'd be happy to answer specific questions. I strongly recommend reading Q1A and Q1E