Abstract: In modern life, pumps are attached to a huge amount of applications, therefore, some replacement parts should modified and produce in form to be suitable for different configurations. Working with these modification and constraints lead to redesign the geometry to avoid the cavitation phenomena and make the pumps parts as portable as easy to replace at any time. In complex fluid domain like centrifugal pump, there is some sensitivity towards many design parameters and also to some particular objective functions. Investigate and determine the main parameters which have a major effects on the pump performance and efficiency are very important before any further steps. These parameters include contact pressure, Mises stresses, specific speed, coefficient of friction, casing thickness value and clearance between rotor vanes and casing. In this research, the commercial software (Abaqus/CAE) has been adopted as a powerful tool for modelling and simulation this analysis process. Furthermore, the global sensitivity analysis are used to validate and expand the results. Here, some design variables are used to be fixed, like phase angle and angle of blades. In this global sensitivity process, many and different models are built to facilitate the analysis. Meanwhile, in this research, the interactions between some impacts which effects on performances of impellers are resolved. It’s found that, the design parameters that has most effecting in reducing stresses can be identifies through sensitivity analysis. Results revealed that, the contact pressure, Mises stresses and the shape parameter (t) are the most effecting parameters. Simulation results show that, there’s a positive relationship between specific speed and efficiency. Furthermore, it’s found that the blade angle influenceon vane performances can be neglected comparing with other design variables. The finding of optimization analysis shows that, the efficiency of optimized model is higher than the conventional type. It’s also concluded that the overall performances will enhance by this type of optimization process. The minimum pressure coefficient and efficiency can improve by (0.35 and 0.4%), respectively.