Most of Time, machines are classified according to their criticity level in process. It’s also a good way to prioritize repairs on them. Sometimes, certain tasks can be done in very short time and with very few resources. So therefore, finding a balance is important in order to accomplish all tasks successfully in short time.

If possible delegate tasks and use all available resources. Try to tackle anything that you can complete quickly, then when you get to the more time consuming tasks you won’t sink the ship if there is a hold up . Use the momentum !Use the 80/20 rule!

When there are several tasks that need to be completed in a short amount of time, and working on them at the same time (to a manageable degree) is not possible, the firsts thing I'd do is consult with my supervisor - mainly to get a better understanding of priorities at a higher level, or at the very least to get advice on how to proceed. At a more personal level - if priorities are unclear or equal between tasks, I'd started with the one that is the most clear concerning which steps need to be taken for completion, and if possible delegate parts of the other tasks to teammates to help ease the workload and at the very least present to the stakeholders that progress is being made to fix the issue.