Decision making on projects is often done in isolated silos, lacking collaboration and communication between teams. This modality often leads to inefficiencies due to late changes in the design and the need for rework. Team moods decay when there is lack of a clearly defined decision-making process, provoking frustration and apathy. This paper presents a case study that demonstrates how the implementation of lean ideas and methods, specifically A3 reports and Choosing by Advantages (CBA), helped a team evolve their process beyond a traditional decision-making strategy. The researchers used a unique approach to observe the decision-making process as conversation for action to help the team overcome challenges. This paper quantifies the impacts of simultaneously implementing A3 and CBA in terms of saving money and reducing time in meetings. In addition, the research presents qualitative results in terms of improving the project design and creating a team capable of making efficient and sound decisions.