Designing a cash register UI for a hungarian brand (Norbi Update). It's not an easy thing. Actually it was a so challenging:
I've never designed ... so how should I start this project?
I've checked cash registers in shops which has a touch UI and try to memorize the UI and on the other hand I try to search for cash register UIs in the net. I found not too many. Though these two source was enough to have basic ideas about how it should look like.
As a preparation for the whole project we decided to go to some of the franchise's shops and interviewing them in order to understand :
After the interview I started designing an interface.
Then I decided to test it with "real users": I used a pure wireframe format without any color to make sure we are in the right way.
After that test I had to do a very little modification then a graphic designer finished adding "colors" to the UI.