A few decades ago, Tom Armstrong took a course on mathematical modeling taught by Jim Rock. Most of the course was theory, with a few calculations of steady state solutions of the equations. A year or three later, Tom was assisting Mark Nicas in delivering a new version of a mathematical modeling PDC. Somehow, the issue of computational tools arose. Mark did most work in Matlab. Mike Jayjock had shared some of his modeling in BASIC and spreadsheets. Tom had started some of the modeling equations in MS Excel. In discussion, Mark and Tom agreed to explore further spreadsheet development and compared results to Mark’s Matlab setup. When Daniel Drolet saw one of the first versions, circa 1997, he mentioned that he could make in more easily useable. That led to the Tom and Daniel collaboration yielding IH Mod 1.0 around 2008. The setup of the equations were validated by independent verification by EASC members including James Stewart, Mark Nicas, Fred Boelter, Chris Keil and Mark Nicas. Additional support from Mike Jayjock, Susan Arnold and Renee Anthony were invaluable.
Although Monte Carlo Simulations (MCS) in IH Mod 1.0 COULD be done using software such as @Risk or ModelRisk, it was tedious and less than fully satisfactory. Daniel Drolet figured out how to do the MCS calculations for IH Mod right in MS Excel. That led with much work on Daniels part, to the release of IH Mod 2.0 in 2018.