The A3 Report is one of the most powerful tools in the lean toolset. Although it looks pretty simple, it is one of the most effective means of pulling together many of the tools used in problem solving and reporting. You can't go wrong by learning how to use this tool and then implementing it within your organization.
People will bring a printout of an A3 Report with them to the relevant meeting, confident that everyone they showed it to understands its meaning. The A3s become part of common vocabulary, speeding up communication and the organization as a whole.