With the nature of our production process, because so many types of cabinets come through the line and most are different from each other, assembly is one of our biggest bottlenecks. The biggest struggle right now is that tall cabinets require a lot of time and work to fit and, usually, re-fit parts together. It usually gets assembled with the division upside down before it gets assembled correctly. 

I've been asked if I can change the dowels to have a hidden indicator, either an extra dowel or a slightly different dowel pattern for either the top or the bottom, so that the builders can assemble the cabinets with ease and a little more efficiency. The idea is to make it to where the cabinets can only be assembled one way.

The problem is, I'm not really certain if this is possible, much less how to go about doing this.

Any ideas, or even other solutions that have worked for you to make assembly an easier task during production?