A hydraulic press can make 900 pieces/week. Your company can sell those in six weeks. A robotic welder is a bottleneck in the flow of a product line for which demand exceeds supply; any decrease means lost revenue. What should you do if both machines go down simultaneously?
You already have PMs scheduled for another bottleneck machine today. How do you prioritize if you have only enough crew for one machine at a time? That robotic welder needs to run as much as possible and it's down, so it takes priority over the other two. The other bottleneck machine isn't down, so it can wait for its PM work until the robotic welder is back in operation. The hydraulic press is down, but it can make far more than your company can sell so it can be down for quite a while before there's really a problem.
What if the hydraulic press has a broken safety switch that allows it to run while the light curtain boundary is breached? Safety takes precedence over production, but you don’t have to fix the press immediately. Take it out of service. Then, fix it when the other two jobs are done.