Human behavior and domain knowledge in parameter design of complex systems

The design of complex systems involves selecting design parameters to satisfy the required constraints while meeting desired performance objectives. These parameters are often coupled and their relationships not easily understood. This paper presents results of an experiment to understand how designers solve parameter design problems, in the context of desalination systems. Subjects with different desalination expertise were asked to complete design tasks involving seawater reverse osmosis plants. Results confirmed that designers had difficulties understanding the sensitivity of coupled variables. More desalination knowledge was linked to better performance and designers with limited desalination knowledge tended to perform the worst due to having partial or incorrect domain knowledge. These findings have implications in design tool development and education.