The defective array elements which are unavoidable due to the long full-time antenna system operation directly affect its radiation pattern, sidelobe level (SLL), directivity, and the system performance. Therefore, reducing these undesirable effects is a main interest in designing such arrays in practice. In this paper, a partially compensating method based on the genetic optimization algorithm (GA) is proposed to mainly reduce those undesirable effects of the defected elements. Unlike the existing fully compensating methods where all of their active elements were optimized to compensate for the effects of the defected elements, the proposed method optimizes the excitation weights of some optimally selected active-elements. Thus, the whole array elements do not need to be redesigned again as in the case of the fully compensating methods. This greatly simplifies the design implementation of these arrays. Moreover, a very large defective percentage ranging from 5% up to 50% has been considered to demonstrate the effectiveness of the proposed method. Furthermore, the drawback effects of the randomly failing elements at the array center have been highlighted, and some suggestions have been provided.