How long is too long?

Hi everyone,

  Elearning newbie here.  Just got my first elearning project using Storyline. I have to build a course to help our people improve their inspection results with ordnance (weapons, ammo and pyrotechnics). Pretty high risk.

  I have been going through the steps of creating content flow and storyboards and it is a lot of material to cover. It could potentially make for a really long course. 3-4 hours maybe (or longer)

  My question: Should I create one long course that learners can leave and come back to or... I had an idea of splitting the course up into several elearning mini-courses.

  What are your thoughts?

Thanks,

Cooper