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Spreadsheet error rates

…but is reasonably consistent with the field audit results discussed above. Lawrence and Lee found that 30% of the spreadsheets they reviewed had errors in over 10% of unique formulae; one spreadsheet had errors in more than one in five of unique formulae. Interestingly, this was the smallest spreadsheet, showing that error rates don’t necessarily…

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Newsletter Nov 2004

…spam filters. =============== 2. More spreadsheet woes While I’m on the topic of model errors, let’s get a bit more specific about spreadsheet errors. There have been good ones recently – Patrick O’Beirne maintains a good list at http://www.eusprig.org/stories.htm. Just read it if you don’t believe that there are large numbers of spreadsheet errors, and…

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Newsletter Mar 2003

…test? You should test your spreadsheets because they may contain errors (see item 1). People fail to test their spreadsheets because they underestimate the benefits of doing so: mainly, they simply don’t know how many spreadsheets contain errors. Think about it for a moment. Do 10% of spreadsheets contain errors? Or 20% (for the pessimists…

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Project financing spreadsheets

…saying that in four of the models they reviewed over 15% of the unique spreadsheet formulae contained errors, and that one model had errors in over one in five of the formulae. This model was one of the smaller ones, too, so it’s no use saying “it’s only a small model, so it’ll be OK”….

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Newsletter Mar 2006

…rather than after. Making an effort to avoid mistakes in spreadsheets is not enough: what is needed is an effective development process, which includes appropriate testing and review stages. If there are routine ways of performing testing and review they are less likely to be skipped, and more likely to catch errors. And spreadsheet errors

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Newsletter Sep 2004

…models (100%) that they reviewed contained errors. They are saying that in four of the models they reviewed over 15% of the unique spreadsheet formulae contained errors, and that one model had errors in over one in five of the formulae. This model was one of the smaller ones, too, so it’s no use saying…

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Provident Financial modelling problem

…as “analysts” rather than “programmers” or “developers” some sort of user-developed software seems likely), this is a classic example of a spreadsheet being built as a one-off and then reused without adequate controls. Later pools must have used a different spreadsheet, as they were not subject to the same restatement. The CFO has more confidence…

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TransAlta Corporation

Next time you paste some figures into a spreadsheet, be afraid. Be very afraid. Someone at TransAlta Corporation managed to lose $24m (Canadian) through a “clerical error” in pasting into an Excel spreadsheet. The spreadsheet in question was used to submit bids to the New York Independent System Operator (New York ISO) for May 2003…

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Nevada City budget problems

…finance director about a day to fix it. As he was doing so, he found other errors. Obviously the spreadsheet had changed after it had been printed out. We have no information about how the error was introduced. We are not told whether the other errors that were found and corrected were actually in the…

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Types of user

A spreadsheet may have the following types of user: A Viewer looks at the results, but makes no changes. A Viewer may never see the actual spreadsheet, but only printouts of selected parts, but they are still using the spreadsheet. A Player changes input cell values, but doesn’t change formulae and layouts. They may execute…