A methodology for planning, assembling follow-up and reporting performance indicators is discussed in this paper as a case in the prototypes management at the Mercedes-Benz Brazil. In the planning module of this tool, the resources allocation task is supported by lessons learned from similar projects done previously in order to achieve the project timeline. Additionally, an assembling follow-up module can be used to manually update each project status and employed resources. The planned schedule and the assembling status are automatically compared generating performance indicators in a weekly report. Based on these results, contingency mechanisms, resources relocations and/or a new ranking of projects priorities can be supported by reliable data, avoiding financial losses or delivering delays. The prototype assembling management tool runs totally integrated with a shop floor management methodology and together these systems can monitor resources like operators, machines or bench tests in a consistent database.