The present work evaluates the impact of alterable manufacturing and formulation factors on the physicomechanical properties of Acetaminophen (APAP); a poorly compressible Active Pharmaceutical Ingredient (API). By varying the amount of APAP and particle size of Microcrystalline Cellulose (MCC), six different formulations were prepared. These formulations were compressed into tablets at different compression pressures and speeds. The porosity of the tablets was evaluated through "outof-die" Heckel analysis. Furthermore, the qualitative and quantitative relationships of (i) Percentage of APAP, (ii) Compression pressures, (iii) Compression speeds, and (iv) Particle size of MCC with tablet porosity were evaluated by principle component analysis (PCA) and principle component regression (PCR). Heckel analysis revealed that increasing the ratio of APAP to MCC in the formulation adds its compressibility when the MCC particle size is similar to that of APAP. While, using large MCC particle size increases the compressibility due to fragmentation of particles, using MCC of small particle size increases the compressibility to a higher extend. The PCA indicated that the percentage of APAP, compression pressure and particle size of MCC are all correlated negatively to tablet porosity. Furthermore, the PCR quantified these correlations to show that tablet porosity was predominantly dependent on compression pressure followed by MCC particle size, APAP percentage, and compression speed in descending order. This work provides an insight into the collective impact of manufacturing and formulation factors on the mechanical properties of tablets, which can help developing an optimized multivariate function to ensure tablet quality of poorly compressible APIs.