The Effect of Delocalized Plans on the Maintainability of Spreadsheets A Controlled Experiment

Spreadsheets are widely used in industry. Companies take important decisions based on information coming from spreadsheets. But, spreadsheets also suffer from typical software maintenance issues. Previous research shows that they contain code smells, lack documentation and testing, have a long live span and during this life span are transferred multiple times from one user to another. To obtain a better understanding of how the maintainability of spreadsheets can be improved, we focus in this paper on spreadsheet comprehension. We analyze the relation between the organization of formulas in a spreadsheet and its maintainability. To that end, we conduct a controlled experiment with 107 spreadsheet users, divided into two groups. One group receives a model where the formals are organized in such a way that all related components are grouped closely together, the other group receives a model where the components are spread far and wide in the spreadsheet. All subjects have to perform the same set of comprehension tasks on their spreadsheet. The results indicate that the way formulas are organized, indeed influences the performance of the subjects in their ability to comprehend and adapt the spreadsheet. Especially for the comprehension tasks, the subjects performed better on the model were the data was grouped closely together. For the adaptation tasks, we found that the way the formulas were constructed influenced the performance of the subjects more than the organization of the formulas itself.