Rutgers Business School professor's teaching tool aids Washington State toxic soil cleanup

Wednesday, October 21, 2009

When the State of Washington Department of Ecology needed a calculation tool to determine whether soil cleanup levels for toxic sites should be adjusted, it turned to an Excel add-in designed by Professor Jonathan Eckstein at Rutgers Business School.

Originally developed as a teaching tool to instruct undergraduates in computer simulation and probability, YASAI (Yet Another Simulation Add-In) is an open-source program that allows Excel to perform Monte Carlo simulation. Monte Carlo simulation is a technique used to analyze situations involving uncertainly, such as fluctuating materials costs or customer demand.

“It’s not the first Monte Carlo add-in for Excel, but it’s simple,” said Eckstein. First implemented as a senior honors project by Steven Riedmueller under Eckstein’s guidance, the goal was to develop an add-in for Eckstein’s Operations Management Class that would be simple to install on students’ computers, easily understood, and free. While commercial Monte Carlo add-ins exist, they tend to be relatively expensive and complicated, said Eckstein. Later, other Rutgers undergraduates added more features to YASAI, also under Eckstein’s direction.

YASAI, unlike the commercial programs, was developed entirely in Visual Basic, making all its code visible from Excel. In fact, Eckstein and Riedmueller were so successful in their goal of developing a simple—yet effective—add-in that Greg Pelletier, senior environmental engineer with the Washington State Department of Ecology’s Environmental Assessment Program, was able to easily modify the code so YASAI could be used to determine if changes should be made to the state’s soil cleanup levels.

“It’s the best open-source add-in for Excel that I have found to run Monte Carlo simulations,” said Pelletier. “All the programming is accessible, the coding is not hidden, which made it easy for me to add the features I needed to run our models.”

With the commercial package he had been using, not only was it impossible to make changes, he also could not examine how computations were being determined. “It was too much of a black box for us,” said Pelletier. “With YASAI, we could see the detail we needed.”

The Department of Ecology wanted to know if new scientific information meant it should revisit the methods and procedures used to establish risk-based standards for the cleanup of hazardous wastes.

“Using the YASAI simulation tool with Greg’s Visual Basic additions allowed us to evaluate whether our current exposure model should be adjusted,” said Craig McCormack, toxicologist with the Department and Ecology. “The goal of our probabilistic exposure analysis is to provide risk managers with tools to make better risk management decisions. Based on the simulations done with YASAI, we now have an assessment of whether various exposure pathway models are reasonably protective based on defined exposure distributions and simulations.”

Eckstein explained he developed YASAI to teach business students that when dealing with uncertainty, they do not need to rely solely on intuition. Instead, they can use probability models to weigh the possible outcomes of their decisions. He said he was not surprised to learn that the add-in has been used as part of a major environmental assessment, as he has been contacted several times by businesses and organizations that have found YASAI useful. “After all,” he adds, “that’s what open source is all about.”

Research applications like Professor Eckstein’s YASAI excel add-in demonstrate Rutgers Business School’s commitment to provide students the business, science and technology credentials to drive local, national and global business.

To learn more about YASAI and the features added by the State of Washington, go to and

Written By Kathleen Brunet Eagan

TAGS: Information Systems Jonathan Eckstein Research