in house maintenance staff often modify existing equipment to make it do new things.

As long as there is some engineering oversight for situations that push the limit, so it does not collapse, explode, etc.

That said, these people must have training and familiarity with the equipment. Some things require some engineering certification, cranes, mine trams etc, but adapting a cotton picker to spinach picking seems a reasonable adaption because the tasks and load on the two machines are similar

Some determine "experts" as have the book knowledge but absolutely no practical experience, to make this process work.

Some things require some engineering certification,

Look at the humble beginings of how John Deere.

having at least a working knowledge of pumps and valves, flow control, cylinders, actuators and components, and mobile hydraulics as they relate to hydraulics is a minimum qualification when operating a farm successfully.

in every organization i was in, there was a suggestion program..

come to think of it , none of mine ...

well maybe one did get implimented...

Absolutely. This is the essence of innovation. I would however, make sure that myself or the fabricators were sufficiently skilled to do the modification safely.

This is very common in the field of agriculture. Take a look at Farm Show. I always get a kick out of some of the things they do.

You might be interested in the Ebooks on Industrial Hydraulics. No Mobile equipment but the principles are the same. Man diference is in the makeup of some of the components.

http://www.hydraulicspneumatics.com/200/eBooks/

Basics through Circuit design in the two books presented.