The redundancy allocation problem (RAP) for seriesparallel system is a system design problem by selecting an appropriate number of components from multiple choices for desired objectives, such as maximizing system reliability, minimizing system cost. RAP has been extensively studied in the last decades. The majority of existing RAP models assume that components for selection are from homogeneous populations. However, due to manufacturing difficulties and variations in raw materials, many manufactured components/parts are heterogeneous, consisting of multiple subpopulations. In this research, we consider a typical RAP with the objective of maximizing the system reliability subject to the constraint of system cost. Components in each choice are assumed to be degradation-based, and each choice consists one normal subpopulation and several abnormal subpopulations. Numerical examples are investigated to illustrate the impact of the component heterogeneity.