Large Scale What-if Queries: A Case Study Using COCOMO-II simulations, effort estimation, risk assessment, COCOMO-II When a lack of data inhibits decision making, large scale what-if queries can be conducted over the uncertain parameter ranges. Such what-if queries can generate an overwhelming amount of data. In the case study explored here, machine learning was used to summarize the output of a Monte Carlo simulation of the COCOMO-II software effort estimation model. Based on that summary, key risk reduction factors were identified. This method of understanding models is general to many application areas.