In this study, for composite patch repairs, the impact degrees of patch configuration and patch sizes on repair performance were determined and compared with each other. First, stress intensity factor (SIF) values were calculated by using the Finite Element Method for tensile loading in an aluminum plate with center cracks, in unpatched situation. In this model, the repair was made by forming single and double sided patches and adhesive volumes too. The SIF values are recalculated for different patch thicknesses, widths, and crack lengths. The criterion that determines the impact degrees of the examined parameters was accepted to be the reduction rate in the SIF values. The results show that even the most disadvantageous patch application contributes significantly to the repair performance and that the application itself is the most effective factor. The second most effective parameter is patch configuration; the patch sizes have much less impact degree.