In medical device projects that I have worked on and am working on, one of our most important external stakeholders are our suppliers. We do not do any in house manufacturing, so we rely on vendors to manufacture all of our product. Since they are such an important stakeholder, it is critical to set expectations with your suppliers and maintain a good relationship with them throughout the project. Similar to how transparency is critical to the internal project team, it is also important to maintain transparency with your suppliers, although it can be a little more difficult because you do have to be careful how much you share with your suppliers, as they are often manufacturing products for your competitors as well.