In my time at the local agency Tovarna idej, I got the project of redesigning a ticketing system for a cinema chain. They were using a system that was a little outdated and they didn't really use all of it. Our goal was to optimize the system and therefore make their work easier and quicker.
It was a behemoth of a system - everything from selling tickets and concession things, creating weekly timetables for the films being played, putting in all the new movie info (the system was connected to their webpage so that's where all the info would be seen as well), to all the distributors' cuts, loyalty cards, prices, creating theatre layouts, and register closure (that needs to connect with their accounting platform).
The system would be used by different people with different tasks, so we needed to include user roles - specific to those the user will see only what they have permission to see (i.e. a cashier will not see the distributor's cuts, just the ticketing and concession part).
With some initial trouble regarding what functionalities to include we went down this path:
figure out what functionalities they need
We talked to the employees that use the system daily to get a rough picture of the usage. That way we also wanted to find out what tasks they perform the most, what are the most common things to occur (and which rarely do, but still need to be included).
After we had an outline of the functionalities we:
set down the basic logic of the interface and prepared mockups true to resolution
As the was to also be installed on all the cashier stations with touchscreens it needed to have specific traits (everything you could do, you should be able to do it without a mouse or a physical keyboard).
The final mockups were put into an interactive prototype so we could see if the user journeys and flows work, and the client could get a better idea where our project was headed.
Once the prototypes were tested, some adjustments were made - and onward we went to the visual revamp of the mockups (a.k.a. the graphic design).
We went for simplicity, clarity and high usability. All the main functionalities (especially for the cashier) were instantly apparent, and the additional, rarely used tasks were just a click away.
Gathering feedback from the cashiers they seemed to like the change and the ease-of-use it brought with it.
After an initial testing phase of the system on site it has been included in their daily work.