Domain-partition (DP) model is a general model for reliability maximization problem under given redundancy. In this paper, an improved DP model is used to formulate a reconfiguration computing based fault tolerant system which is self-repairable in case of failure, and is solved as a nonlinear planning problem. The assumptions made in previous work are relaxed. An improved algorithm is proposed to reduce the time cost for calculating the reliability. Experiments on ITC'99 benchmark circuits are carried out. Results show the proposed approach outperforms previous works in failure rate with less memory cost to store configurations. Keywords-reconfigurable system; fault tolerant; domainpartition