Abstract: For future applications, it is important to develop systems using small objects. Such systems must be able to provide uninterrupted services even when some small objects stop. Replicating such objects is one way to do this. However, introducing some type of redundancy into systems generally adds some overhead. Our proposed model reduces this overhead. It is implemented with multi-threaded execution for applications in actual systems. We measured the performance of an implementation for applications connected to databases. The results show that the overhead for ordinary execution and the time required to switch the replicas are both acceptably small. This technique will therefore play an important role in future systems.