When an application is running, it normally can not be started a second time. If you run it again from the dock, it will bring up the current running to the front.
In some situations, it would be helpful to start it again – especially system applications like the network scanner.
With the help of Path Finder it is no big deal to start a running application as much times as you need it, by just right-clicking on the app in process sidebar and selecting “new instance“.
With that way it is easy to manage some unique tasks as a mass task.