"Assessing climate model software quality: a defect density analysis of three models"
J. Pipitone and S. Easterbrook, Geosci. Model Dev., 5, 1009-1022, 2012conclude:
The results of our defect density analysis of three leading climate models show that they each have a very low defect density across several releases. A low defect density suggests that the models are of high software quality, but we have only looked at one of many possible quality metrics. Knowing which metrics are relevant to climate modelling software quality, and understanding precisely how they correspond the climate modellers notions of software quality (as well as our own) is the next challenge to take on in order to achieve a more thorough assessment of climate model software quality.