On a mobile application project, an experienced team member has started missing deadlines, and these delays will affect implementation. What should the project manager do next?

The project manager's first step should be to meet with the team member to understand the root cause of the missed deadlines. This direct, one-on-one communication respects the individual and allows for a private discussion to uncover any personal or professional challenges affecting performance. Assigning another resource without understanding the problem might not solve the underlying issue and could be an inefficient use of resources. Checking with the functional manager is a secondary step, potentially useful if the direct conversation doesn't yield a clear understanding or if the issue is systemic. Holding a team meeting for motivation is too general and doesn't address the specific problem with one team member; it might also embarrass the individual.