The journalists had access to the contracts and official documents for the projects carried out by Odebrecht between 2001 and 2016, employing the prevailing transparency law in their country to request access to information, and revising the public databases of the institutions responsible for executing the works and the official reports by the Executive and Judicial branches or Congress. In the cases in which the information was not published - though it should be accessible to citizens -, the data was obtained through interviews with highly reliable sources.

The reporters entered the data from the documents and various sources into an Excel spreadsheet shared on Google Drive. Since this document was online, the updates, comments and consultations were carried out in real time. The columns of the data were organized according to journalistic criteria determined by the team as part of the work hypothesis: project name, initial and final budget, budgetary increases, government that awarded the work, date of execution, addenda approved and investigations underway, among other fields.

After the construction and coordination to fill in the data, the Convoca team began the process of cleaning the information (data format, names, among others). The team also ensured that each data item included in the Excel spreadsheet was supported by an official document or source, to check the data. This process also involved speaking to each journalist about the source of the information. The verified data on the initial and final budget of the works included in the tools was sent to Odebrecht in Sao Paulo, Brazil, so that the information could be compared. The journalists working on the project also searched for the company’s version of the information for their countries.

For the analysis, the journalists at Convoca in Peru, ColombiaCheck in Colombia and Plaza Pública in Guatemala established a methodology. To establish the cost overruns for the projects studied in the tool, a simple operation was carried out: the final budget was deducted from the initial budget, taking into account the original currency that appears in the project contracts. The result was converted into dollars where necessary, since presenting all results in a single currency would make them comprehensible for any reader worldwide. For the latter operation, we took into account the exchange rate on the date of the most updated final budget, according to the various sources consulted. This data having been verified, it was analyzed in dynamic tables to establish rankings and determine the first findings for the investigation. Simultaneously, the journalists have constructed other databases to pursue the investigation in greater depth and include other stories linked to this topic.

The final data was transferred to the ‘ViaSobrecosto’ tool developed by the programmers at Convoca, and includes a country-based search tool, a map, a fact sheet for each project and rankings on the principal findings. The tool can also be added to the webpages of the media outlets and organizations that participated in the collaborative project ‘Investiga Lava Jato.’