Worldwide, there is significant ongoing research dedicated to the experimental search for neutrinoless double beta decay (0 \(\nu \beta \beta \) ). The reason lies in the fact that the most sensitive experimental avenue to determine if neutrinos are Majorana particles is through the search for 0 \(\nu \beta \beta \) , which further offers insights into the absolute mass scale of neutrinos and the mechanism behind mass generation. The forthcoming 0 \(\nu \beta \beta \) experiments target the detection of signals within the inverted mass ordering (IO) and advancing their sensitivity into the normal ordering (NO) regimes. Prior to the execution of experiments, we undertake a quantitative assessment of the projected experimental sensitivity, focusing primarily on the discovery potentials. We analyze the sensitivity of the counting method using full Poisson statistics and compare the results with those obtained from its continuous approximation. Sensitivity can be further improved by incorporating additional measurable signatures, such as energy, which is accounted for in a maximum likelihood analysis. Our research highlights a practical approach for assessing the potential sensitivity of future 0 \(\nu \beta \beta \) -projects based on their anticipated backgrounds before their execution.