Every project manager has one key role to play: scope cop. But it’s a job you can’t do in isolation. You need to share nitty-gritty details and related financials with your team members on at least a weekly basis (more often than that in some industries) so they’ll support your efforts instead of undermining them with the best of intentions. It’s the only way, aside from sheer luck, that you’ll even come close to hitting your deadlines and your budget.