Use PS to start and stop a process depending upon the starting and stopping of another process

I was trying to use Task Scheduler to start Skype for Business after Outlook had started (already using it to start Outlook), and to kill SfB after Outlook was terminated. Apparently, that's beyond TS's capabilities; it was suggested I look here for help on scripting this operation. The PS scripts to start and stop Skype were simple enough; but finding how to trigger them is a galactic hemorrhoid. I would appreciate any assistance on automating this process — perhaps more accurately, these processes.

Many thanks.