For example, it can construct and operate foraging systems to procure fuel or materials, waste disposal systems, or transporters to carry replica shops to other locations. At this point it is clear that the effect of a self-replicating system on its environment may take many forms dependent on the external process program. Using such a program, the scope of the system can be extended by construction of machines and structures capable of producing complex subsystems including mineral processing plants, solar energy power supplies, etc. They would differ only by addition of the external process program segment peculiar to each type. Reliability and redundancy.
Reliability is a primary concern, especially in the case of self-replicating processes.
Two ideas are most important here. First, the self-replicating program accuracy can be verified by comparison with other replicas of the same program. If a discrepancy is found between two self-replicating programs, a third or fourth replica can be consulted and the error pinpointed and corrected. The test of correctness is the ability to self-replicate. Second, machines tend to wear, and ultimately to fail, from excessive use.