Guidelines:
- Treating spreadsheets as a simple tool is a mistake
- Recognize that even small spreadsheets have risks
We know that spreadsheets are important for many applications, including informing decision making. We also know that spreadsheets have real and substantial risks.
Therefore, an obvious question is: Why is spreadsheet practice generally so poor?
Spreadsheets demand serious attention
The answer is that we tend to treat spreadsheets as being simple, below the threshold that demands serious attention. Few organizations have formal practices for spreadsheets, with most IT departments deeming spreadsheets to be the users' problem. Managers typically consider spreadsheets to be a simple tool, with no need for oversight or training beyond the basics. However, they are misguided. In practice, many spreadsheets are sophisticated applications that we use in complex ways.
Developing and using spreadsheets is often far from easy – as anyone who has struggled with a spreadsheet will attest. Yet, once a spreadsheet is complete, we often treat it as if there's nothing complex about it at all.
A key issue is that the formulae are hidden behind the spreadsheet's presentation layer. A nicely formatted spreadsheet may disguise a tangled mess of convoluted and complex formulae. We tend to equate nice presentation with good design and correctness, but often that is not true.
Even small spreadsheets have errors
Research shows that even small spreadsheets often contain errors. For example, in one experiment:
- Students develop and debug a spreadsheet model from a word problem.
- This model consists of modelling a bid to build a wall.
- The problem is designed to be relatively simple and domain-free.
- In the development phase, even though the model contains only a few dozen cells, 38% of the models contained an error.
- In a debugging phase, subjects tried to debug their own models. Only 16% found and corrected their errors.
- The conclusion was that even with a simple model, development and debugging are problematic.
This exercise, known as "The Wall Problem", has been replicated many times, with similar results. Experience shows that larger, more complex spreadsheets are even riskier.
Because most managers are unaware of the risks, they do not give spreadsheets the attention that their importance deserves. This lack of attention allows the use of poor practices, further increasing the already largely unrecognised risks.
