Like anime made for television broadcast, OVAs are sub-divided into episodes. OVA media (tapes, laserdiscs, or DVDs) usually contain just one episode each. Episode length varies from title to title: each episode may run from a few minutes to two hours or more. An episode length of 30 minutes occurs quite commonly, but no standard length exists. In some cases, the length of episodes in a specific OVA may vary greatly, for example in GaoGaiGar FINAL, the first 7 episodes last around 30 minutes, while the last episode lasts 50 minutes; the OVA Key the Metal Idol consists of 15 separate episodes, ranging in length from 20 minutes to nearly two hours each; The OVA Hellsing Ultimate had released 10 episodes, ranging from 42 minutes to 56 minutes. An OVA series can run anywhere from a single episode (essentially a direct-to-video movie) to dozens of episodes in length. Probably the longest OVA series ever made, Legend of the Galactic Heroes, spanned 110 main episodes and 52 gaiden episodes.
A great example of using animation for explanation is TED-Ed. If you are not signed up to their YouTube channel yet, it’s just about time. It has over 3 million subscribers and is one of the most popular educational channels on YouTube. Most videos created by the team use animation. It simplifies otherwise difficult topics like how the food you eat affects your brain or the physics of the “hardest move” in ballet.
There is a excellent video training (about 2 hours) how you can use Explaindio 4.0 for the best results. This training isn’t a part of the program or an upsell. It’s a stand-alone product made by Scott Hamlin and called Explaindio For Professionals ($27.00). I can highly recommend this quality training. It’ll save you time and many and fore all give you great ideas and examples how to use the software without any prior experience.