A decomposition-based approach to spreadsheet testing and debugging

Spreadsheets serve as a basis for decision-making processes in many companies and bugs in spreadsheets can therefore represent a considerable risk to businesses. Systematic tests can help to locate such bugs, but providing test cases can be cumbersome and complex for large real-world spreadsheets. To make the specification of test cases easier, we propose to split spreadsheets into smaller logically connected parts (called fragments) which can be individually tested for correctness. We present an algorithmic approach to compute such fragments, which we validated with a laboratory study in the form of a spreadsheet debugging exercise involving 57 subjects. The results show that the fragmentation approach can help to significantly reduce the required efforts to test a spreadsheet.