This paper combines checkpointing and replication for the reliable execution of linear workflows. While both methods have been studied separately, their combination has not yet been investigated despite its promising potential to minimize the execution time of linear workflows in failure-prone environments. The combination raises new problems: for each task, we have to decide whether to checkpoint and/or replicate it. We provide an optimal dynamic programming algorithm of quadratic complexity to solve both problems. This dynamic programming algorithm has been validated through extensive simulations that reveal the conditions in which checkpointing only, replication only, or the combination of both techniques lead to improved performance.