A tool for visual analysis of tax-free sales data

Schiphol - Amsterdam Airport collects a huge amount of data of the usage of the airport, from flights, to parking, to baggage handling, and more. One of these data sets is about tax-free sales. The airport wanted to have a tool for visual analysis of tax-ree sales data where they were able to see the data on a map of the airport. The result of their analysis is used in reports and presentations.


Schiphol has different groups of analysts, specializing in particular data sets. I was asked by the group of analysist that work with tax-free sales data to create a tool that helps them to analyse their data, and especially showing the data on a map of the airport, as this has not been done before. The data set also contained information of the gates that were used by people who had purchased items tax-free. This additional data allowed for the creation of a network between gates and shops based on sales data. Both the map and the network were new ways to analyze the data.


The tool allows for loading different data sets for different periods. Once loaded, all the data is shown at once. The user can then filter the data with the filters on the right (airline, destination, shopping area, etc.) and the bottom (time periode, amount of revenue, etc.). The map can be interactively zoomed, and shops and gates are clickable, showing the network for the selected shop or gate.

At the bottom left the user has options to manipulate the visualization itself (see image above) to create an optimal representation that communicates the message clearly, for instance: showing or hiding labels, increasing or decreasing transparency or circle size, etc.