Birgit Hofer & Franz Wotawa
Locating faults in spreadsheets can be difficult. Therefore, tools supporting the localization of faults are needed.
Model-based software debugging (MBSD) is a promising fault localization technique. This paper presents a novel dependency-based model that can be used in MBSD. This model allows improvements of the diagnostic accuracy while keeping the computation times short.
In an empirical evaluation, we show that dependency-based models of spreadsheets whose value-based models are often not solvable in an acceptable amount of time can be solved in less than one second. Furthermore, we show that the amount of diagnoses obtained through dependency-based models is reduced by 15% on average when using the novel model instead of the original dependency-based model.
The short computation time and the improved diagnostic accuracy enable the usage of model-based debugging for spreadsheets in practice.
Figure (a) shows the normal (or value) view of this faulty spreadsheet variant. Figure (b) shows the formula view of the same spreadsheet. The output cells of the spreadsheet are shaded in gray.
The faulty cell D5 is highlighted with a red box. The fault manifests in the value of the output cell D7. The expected value for this cell is 78.6%.
2014, First Workshop on Software Engineering Methods in Spreadsheets, July