Testing and Refactoring Spreadsheets - Felienne Hermans at Eusprig 2014

Testing and Refactoring

Spreadsheets

Felienne HermansDelft University of Technology

Felienne HermansDelft University of Technology

(@felienne)

Testing and Refactoring

Spreadsheets

95% of all U.S. firms use spreadsheets for financial reporting

90% of all analysts in industry perform calculations in spreadsheets

Importance can grow over time

And, spreadsheet exist‘under the radar’

Only 33% of spreadsheets has a manual

Complex spreadsheets without documentation can lead to serious errors

The European Spreadsheet Risk Interest Group (Eusprig.org) collects horror stories

Why?

No documentation, errors, long lifeIt looks like…?

No documentation, errors, long lifeIt looks like software!

For software, tools have been created to

help programmers write good code

We bring quality tools to spreadsheets

BumbleBee: A tool for spreadsheet

improvement

But, not all transformations have to be

behavior preserving

You can download BumbleBee frommy website (felienne.com)

The transformations are entirely programmable, with a small language

Expector: A tool for spreadsheet testing

These test formulas can be exploited

Our tool Expector can find test formulas

Expector helps users to understand robustness of their spreadsheets

More info? Over drinks, send me an email (f.f.j.hermans@tudelft.nl) or visit felienne.com