There is a popular saying in American folklore: "You can lead a horse to water but you can't make it drink." The analogy fits well for people: You can assign them to a project but you cannot force them to perform. At least that is the case for project managers, who often lack formal authority over people. Project managers, therefore, must provide the incentives for people to achieve the vision for their projects. The best way to make that happen is to encourage involvement in a manner that generates sustained commitment.