I believe that in any project, setting milestone is one of the most important aspects of the project. Milestone planning not only indicates the progress of the project but it maintains the level of accuracy of the project and motivates the team. At times while achieving milestones, we end up discovering new problems or ideas which could bring the success in a project. This may delay accomplishing the milestone that is in the schedule. Therefore, I think missing a milestone is considered both failure and success depending on the situation. However, when there is no any new discovering occurs and still missed the milestone then it is a risk of failure. Failing to meet the deadline for the project to be delivered will set back not only a project manager but also team members.