Errors in Operational Spreadsheets: A Review of the State of the Art

Spreadsheets are thought to be highly prone to errors and misuse. In some documented instances, spreadsheet errors have cost organizations millions of dollars. Given the importance of spreadsheets, little research has been done on how they are used in organizations. We review the existing state of understanding of spreadsheet errors, concentrating on two studies. One analyzes errors in 50 operational spreadsheets; the other studies the quantitative impacts of errors in 25 spreadsheets from five organizations. These studies suggest that counts of error cells are not sufficient to understand the problem of errors. Average error cell counts reported in the literature range from 1 percent to 5 percent depending on definitions and methods used. However, some errors are benign while others are fatal. Furthermore, spreadsheets in some organizations appear to be error-free. Several types of new research are needed to understand the spreadsheet error problem more fully.