In planning, the project manager finds available engineers lack required skills. Outsourcing isn't an option and HR cannot hire or assign new engineers due to budget constraints. What should the project manager do first?

The project manager's primary responsibility is to find a solution within the given constraints. Introducing a mentoring program leverages existing team members' knowledge to upskill those lacking specific skills, directly addressing the skill gap without incurring additional costs or external resources. This is a proactive and cost-effective approach. Changing the scope is a drastic measure that should be a last resort, as it fundamentally alters project objectives. Adding extra time for training might be necessary but doesn't solve the immediate skill gap and could impact the schedule. Using the management reserve for resources is not feasible as the problem states HR cannot hire or assign new engineers due to budget constraints, implying the reserve wouldn't cover this.