I think the most important phase is the initiating phase. It is the most crucial to the success of the whole project; once you have a perfect initiating process everything else falls in place. The first thing when you decide to create a medical device is to look at the needs of the community and the customers that are going to buy the product. Then you look at the similar projects in the past to make the process easier, and look more into the budget and is the project going to make any profit or not. Once you have the team members and you did your research, you can move on to the planning stage. If you did the perfect planning everything else will be smooth and will meet your timeline. In my opinion the easiest step will be the closing phase, because you just finalize the project and again if the initiating phase is perfect, the closing phase will be short and easy.