Monitoring and Controlling - Triple constraints. Throughout the project, a project manager's job is to take corrective action to ensure that a project stays on track with regard to the triple constraints of cost, scope and schedule. We've discussed many ways that a project can get off track - scope (scope creep), costs (overspending, cost increase), and schedule (work taking longer than expected). Based on your work or personal project experience, provide ONE (1) reason that projects can go off track, and what best practice a PM can do to either prevent or overcome it