The SCL model system, an artificial chemistry used for the illustration of the concept autopoiesis, is extended to show self-reproducing entities. The theory of autopoiesis was developed by the biologists Humberto Maturana and Francisco Varela around 1971 to point out the organisation of living systems One of the aims of this theory is to explain the perceived autonomy of living beings. The degree to which the theory succeeds in doing so is investigated. Along the way some ambiguities m the theory are pointed out and suggestions for improvements are made. The conclusion, however, is th at autopoiesis alone is not sufficient for a high degree of autonomy, although it is a step in the right direction. Furthermore it is shown that the entities exhibited in the original SCL model system are not autopoietic, whereas in the extended system they are. Together with SCL some other real and artificial chemical model systems are investigated with respect to the two concepts autonomy and autopoiesis. Furthermore, the utility of autopoiesis as a guiding principle for Artificial Life research is considered. The conclusion is that because autopoiesis suffers from too many ambiguities, other concepts in conjunction with some aspects taken from autopoiesis should be preferred. In particular, the concept of organisation developed by Fontana and Buss (1994) and the theory of collectively auto catalytic networks advanced by Kauffman (1993) seem to be better starting points when working towards a definition of life or concerning questions of the origin of life. Nonetheless, autopoiesis remains useful because some of its variants stress the feature of self-individuation of living beings which the previously mentioned two theories only do to a lesser extent.