**9. Conclusions**

One way of addressing the challenge of complexity in systems engineering is to develop more scientific principles for basing its methods on. In this paper, it is argued that improvement in systems engineering's methods depends on making the principles of systemology, of which systems engineering is a part, more diverse and more scientific. An architecture for systemology is introduced, and this shows how the principles of systemology arise from interdependent processes spanning multiple fields. On this basis a typology is introduced, which can be used to classify systems principles (and consequently the methods that operationalize them). This framework, consisting of an architecture and a typology, can be used to survey and classify the principles and methods currently in use, map vocabularies referring to them, identify key gaps, and expose opportunities for further development. It may, thus, serve as a tool for coordinating collaborative work towards advancing the scope and depth of systemology.

**Acknowledgments:** I would like to thank Julie Billingham, James Martin, Javier Calvo-Amodio, Swaminathan Natarajan, and Jennifer Wilby for support and advice in developing the arguments presented in this paper. I also thank three anonymous reviewers for their helpful comments. Financial and material support for the project was provided by the Centre for Systems Philosophy, INCOSE and the University of Hull's Centre for Systems Studies.

**Conflicts of Interest:** The author declares no conflict of interest.
