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Authors

Stephen G. Powell, Kenneth R. Baker, & Barry Lawson

Abstract

Spreadsheets are used in almost all businesses, for applications ranging from the mundane to the mission-critical. Errors in the data, formulas, or manipulation of spreadsheets could be costly, even devastating.

The received wisdom is that about 5% of all formulas in spreadsheets contain errors, and this rate is consistent across spreadsheets. However, this estimate is based on five studies, some of which are quite informal, and a total of only 43 spreadsheets.

Our research was designed to deepen our understanding of spreadsheet errors. Specifically, we address three questions about errors in operational spreadsheets: what is the average cell error rate, how does it differ among spreadsheets, and what types of errors are most prevalent?

We created a spreadsheet auditing protocol and applied it to 50 diverse operational spreadsheets. We found errors in 0.9% to 1.8% of all formula cells, depending on how errors are defined. We also found that the error rate differed widely from spreadsheet to spreadsheet.

Sample

Distribution of cell error rates
Distribution of cell error rates

46% of our sample spreadsheets had error rates below 2%; 70% had error rates below 5%. However, several spreadsheets had error rates above 10%; in fact one had a cell error rate of 28%.

The average cell error rate (CER) in this sample is 1.79%.

Only 3 out of 50 spreadsheets had no detected errors. That is, 94% of the spreadsheets contained errors.

Publication

2009, Journal of Organizational and End User Computing, Volume 21, Number 3, July-September, pages 24-36

Full article

Errors in operational spreadsheets