There is an illustrative Dilbert cartoon that shows the pointy haired boss asking Dilbert to do project X. Dilbert replies that he already gave him Project Y, so which one is the priority. The boss says, "Can’t you just combine them and do them both?"
As companies get more efficient, they have relied on some heroes to do much. This is one approach.
The challenge to this is overloading. Some heroes do not say no, so their work in process inventory gets bigger and bigger. Little’s Law tells you that the hero’s throughput slows as more items are added. Experience validates this.
Little’s Law shows that fewer work items in process at once is faster when you measure the flow time through the process. Then those things are done, and you can get the next priority item.
Some people still believe in multitasking. They take on 4, 5, or 6 work items at once thinking they can switch back and forth between them and "multi-task". This is bunk. But don’t tell them. Show them. Use an exercise to show this.
What really happens if you measure them is that they context switch. This context switching time adds up and their overall throughput slows.
The solution is WIP limits. This is hard to do in some organizational cultures. People, especially heroes, get pulled by many organizations to help "just for a little while" on this or that and the "little while" extends beyond estimates.
WIP limits for a single person should be set at two (2). This means that if work item #1 is blocked, then the person can work on work item #2 instead. But when you add more than that, their throughput will drop.
We have found that when first teaching Lean-Agile, this is a lesson that can come on another teaching or coaching iteration. You can get positive changes out of Lean-Agile without WIP limits initially. Then later, as the participants grow in their understanding of Lean-Agile principles, teach WIP limits.
Heroes don’t believe it at first. Your management may even initially think it is an approach created by slackers. But when you walk through the data, or better yet, get them to do a brief exercise, they start to trust the idea even if they think it sounds crazy at first.
When you conduct an exercise, consider that Jeff Sutherland has a good one in his book that we have used with organizational leadership teams. Another good exercise involves using a bunch of dice. These exercises are all over the Internet. Find the one you can pull off in your context and use it. It goes over better than a Power Point presentation.