Jcome Cunha,Joo P.Fernandes,Christophe Peixoto, Joo Saraiva

1 HASLab / INESC TEC & Universidade do Minho, Portugal

QUATIC 2012

A Quality Model for Spreadsheet

Why do Spreadsheets matter?

95% of all U.S. firms90% of all analysts in industry50% of all SSs are the basis for decisions

Still...

Economy losses of $10 billion/year!

A recent spreadsheet error...

A Portuguese horror story...

EuSpriG Original Horror Storieshttp://www.eusprig.org/stories.htm

Many more horror stories...

SpreadSheets as SW Languages

In fact Spreadsheets lack advanced mechanisms found in modern languages, namely:

Type and Modular Systems

Abstractions

Debuggers/Profilers/Refactors

Mechanisms for Model-Driven Engineering and Software Evolution!

Best Practice Rules...

This paper

We propose a quality model for spreadsheets based on the widely accepted ISO/IEC 9126 standard for software product quality.

We introduce a set of domain specific metrics for spreadsheets used to measure concrete spreadsheet characteristics.

We calibrate our quality model using a large repository of real-world spreadsheets (EUSES corpus)

Spreadsheets Quality Model: Definition

SpreadSheet Quality Model: Definition

We have adapted the ISO/IEC 9126 to Spreadsheets

SpreadSheet Quality Model: Definition

For example:

Understandability: There are many ways to make a spreadsheet more understandable

1- the separation of the input, computation and output components of the spreadsheet.2- the use of different background colors for different types of data cells.3- a large number of cells makes a spreadsheet hard to understand.

SpreadSheet Quality Model: Calibration

To calibrate our model we need to consider a large repository of spreadsheets: The EUSES corpus (5606 spreadsheets, organized in 6 categories)

SpreadSheet Quality Model: Calibration

The Metrics: we reused SIG Spreadsheets metrics suite

SpreadSheet Quality Model: Calibration

The idea is to compute the metrics in a large set of real-word spreadsheet in order to define metric values that allow us to assign a five star ranking to a spreadsheet.

Repository: EUSES

Metric: Number of Cells

SpreadSheet Quality Model: Calibration

The graphics that represent the aggregation based on the central tendency of the results of computing the metric number of cells

SpreadSheet Quality Model: Calibration

Finally, we are able to define the star ranking intervals for each of the characteristics considered:

SpreadSheet Smells: Catalog Validation

We have implemented both a batch and web-based spreadsheet quality analyzer tools:

SpreadSheet Quality Model: Evaluation

We have developed an equivalent android-based application to assess quality of cloud stored spreadsheets (google docs).

We presented a quality model for spreadsheets.

We have implemented the quality model as three different tools.

We have calibrated our model using the tools a large repository containing real-world spreadsheets.

But,

this is a preliminary result/model. We need to extend our metric suite and, thus, to consider more sub-characteristics of the ISO 9126 std.

Conclusions

SSaaPP SpreadSheets as a Programmin Paradigm (FCT funded)http://ssaapp.di.uminho.pt

AutoSeer - Automated Test Oracles for Software Error Detection (FCT funded)http://www.fe.up.pt/AutoSeer

Research Material