Review of “Complexity – A Guided Tour” (2009) by Melanie Mitchell

2022-06-12

Introduction

The intention with “Complexity – A Guided Tour” is to give an introduction to and an overview of the general field of complexity science, a field which in which common characteristics and principles for complex systems are researched.

The target audience is a general, curious reader with no specific background. Personally, I found it relatively easy to read and follow the text, but I benefitted from having a background in mathematics and computer science. The text is almost free from math, but the thinking which comes from having an education in mathematics or computer science is an advantage to have.

Content

After giving some examples on what constitutes complex systems, Mitchell introduces relevant topics for understanding complexity and provides background and history. The topics include dynamic systems, chaos, information, and computation. Different views on what complexity is and how it can be measured are presented.

Computation is a key concept throughout the book. First, computation is a means to model systems of interest to gain understanding and improve intuition about complexity. Second, it is also a fundamental concept which is relevant to the behaviour of the complex systems which are explored. The information processing which takes place in an ant colony, for instance, can be viewed as a kind of computation going on within the system defined as the colony.

The examples used in the book are from biology (e.g. ant colonies, the brain, the immune system, evolution, genetics), economies, social networks and the internet.

An entire section is devoted to networks and general ideas related to networks. This part highlights how complexity arise from interactions between elements in a set, and the fact that these interactions are a bigger driver of complexity than the size of the set itself.

Even though the book was written many years ago, it does not feel outdated. Of course, major progress may have been made since 2009 within the field, but this would not invalidate the content, I think. But I am curious to know, whether any major breakthroughs have been made, especially in the general questions on how to define “complexity” and “complexity sciences”.

In the closing chapter, Mitchell concludes that the entire field (at the time of writing) is still not well defined, and the field seems to be “a fragmented subject rather than a unified whole”.

Application to Supply Chain Management

There is no doubt that supply chains are complex systems in the sense of the book, and I am sure that there are applications to supply chain management. However, the connections are not so obvious that general complexity theory seems really useful at this time. It would be interesting to know if there were more specific work linking results from complexity to supply chains e.g., modelling supply chains as networks is an obvious idea.

Style

Mitchell mixes presentation of facts with her own perspectives and experiences in a pleasant way. Adding anecdotes and references to other parts of science in particular physics help put the topic into context. Mitchell attempts to balance different views and present both various theories and their criticism. In general, the book has a sober tone, which I like.

Conclusion

“Complexity – A Guided Tour” is a really good introduction if one wants a broad overview of the field of “Complexity”. It is of course a bit annoying that no clear definition of “Complexity” is given, but that is not the fault of the author or the book. In fact, having read the book, one appreciates how complex the field of complexity is, and it has given me a good overview of the topic and the problems which are of interest within the field.

In conclusion, I really enjoyed this book; only in a few places, I think the level of detail was too much. This takes away half a point from a book which I found met its purpose, overlapping nicely with my purpose for reading it.

Rating: 4½ out of 5