Re: When isn't a Work Instruction necessary?
Indeed! Pics and video are great documentation aids. They also turn many a reluctant master into an eager performer/teacher.
May I suggest that explicit can also mean electronically recorded sounds and images? For example, a simple video recording of a process or process steps can convey much more information and much clearer than a written document can.
A picture is worth a thousand words.
A picture is worth a thousand words.

, finally with Management support and positive competition (basically an R&R for the best and most innovative method to display WI et al) we managed to get that done.
. As stated, there is no "requirement" to have work instructions, but most of us find them useful, in whatever purpose we difine them. But, if they are not adding value to your process, you might as well not have them.