This title is misleading as there is no actual "design" happening in the tutorial. This is just another simple "modeling with Solid Works" tutorial of some random piece of mechanical equipment. Actual "design" of a conveyor system or any of the individual pieces of equipment required to make up any real materials handling system, is not just producing another of the many "modeling" videos that turn up on youtube.
Design is a much more complex process. This starts off with the material to be moved, this could be bulk materials, such as, rocks and gravel, or wood chips, packages, as would be in a warehouse-distribution center, moving components along an assembly line, all using conveyor systems and very different types of conveyors are required.
Actual "design starts off with material to be moved, choosing the best type of conveyor for the purpose required, the rate of travel, path of conveyor, mass of product and then working out a specification based on what is required to build your system. Design is a multi-step process. We start with what the system needs to work, once we have a specification to work to, we work though the design calculations required to make a system that will work, then we get into the detail. choose the parts we will get manufactured, and the components we will purchase for the conveyor, We only produce the models and the drawings to make the machine once we have designed the machine we require to perform the task we need it for.
If we have done a good job on the design, the modeling and drawings, the last part of the process isn't that difficult.