While it was probably one of the courses I had the least interest in initially, the Production/Operations Management course brought together some core business concepts for me that are really important. I'd probably still take the lessons from economics over those of operations management given the choice, but they actually work well together.
One of the key concepts we learned was that of kaizen and lean manufacturing. You can go read the Wikipedia article on the topic yourself, but the basic idea is that do something, measure the results, improve the process, and repeat. That's the ultra-simplistic view of it, so nobody quote me about kaizen in your master's thesis based on what I just wrote. The important part is that you look for improvement ideas from everywhere, but you start as close to the process as possible. The worker on the assembly line can probably tell you better what would make that particular job easier than a manager might.
The apocryphal story about the toothpaste factory comes to mind. You can read the fancy version or my two sentence recap. Basically, in order to detect toothpaste boxes that somehow missed getting a tube of toothpaste put inside it and shipped empty to stores and customers, they spent thousands or millions of dollars implementing a scale system that stops the line if an empty box is detected. Very quickly the number of defects drops to zero, not because there are no more empty boxes, but because the guy who had to grab the empty boxes off the scale and restart the line installed a $20 fan to blow the empty boxes into a garbage can just before it hit the scale so he wouldn't have do it by hand.
Who knows if that really happened, but it's a great story anyway.
Something else I learned, which is something I teach today in my project management class is the idea of the critical path. While there are differences with a project being a temporary endeavor and operations being ongoing processes, the idea of the critical path is the same. You track your way through from the beginning to the end of the project or one cycle through a process and determine which tasks have the most direct impact on the length of time it takes to complete the project/process. You can then determine which tasks need the most management attention to keep them on track or come up with potential ways of fast-tracking or crashing the critical path to reduce the amount of time it takes without having an adverse impact on quality.
One last item I always think about related to this class is the movie The Truman Show. It's not that anything we did in the class related at all to the show. I can't even think of any kind of lean manufacturing metaphor that could be related to the movie. It's just that in one class period, we were watching a video about John Deere and their kaizen practices. It was one of those two hour summer classes, where we got a short break in the middle of class. A friend of mine had a copy of The Truman Show in his bag to show as part of a presentation in another class. It was a VHS tape cued up to the scene where he's driving through the forest fires and nuclear accident trying to get out of town. I put the tape into the TV in front of class so when the professor restarted the John Deere video, we got Jim Carrey getting tackled by guys in radiation suits instead. It was great. I thought so anyway. The professor eventually found the tape in its container and put it back in, and I was even able to grab the movie from the desk up front while another student was talking to him after class and thus return it to my friend without the professor knowing who did it. I think deep down inside he would have rather watched a Jim Carrey movie, or maybe that was just me.