Dr Chris Barnes presented the philosophy of modelling complex systems that he has developed over many projects with CSIRO and recently in his company Complex Systems Solutions. In hydrographic modelling, for example, it is known that when rain falls on a catchment, the runoff decays exponentially with time. That rule is observed over a huge range of catchment sizes, but not well understood. Barnes advocates modelling with simple but not necessarily realistic models - a catchment might be well modelled by a pair of buckets with holes, in parallel. He concluded with an overview of a very different problem, understanding Telstra's job sceduling for phone repairs, where a simplification of the queuing priorities led to greatly improved performance.

He recommended Tennyson's Ulysses for motivational purposes.