What steps do you take when the work of a colleague or vender threatens the completion of a project?

When a colleague or vendor's work threatens project completion, I first assess the situation to identify the specific issues causing the delay or problems. I then communicate directly with the individual or team involved to discuss the challenges and collaborate on potential solutions. If necessary, I escalate the matter to management while proposing alternative resources or timelines to ensure project continuity. Throughout the process, I maintain open communication with all stakeholders to keep them informed and aligned.