@DonkeyBot
Revenue Arrangements == 1 contract
Could be 2 sales orders combined, or credits and returns against the same contract (depending on how your systems setup)
Revenue element == diffrent performance obligations in that contract (think sales order lines or credit memo lines).
plan == how do you want to recognize 1 single performance obligation? do you want to recognize it over 1 year, 3 years, 20 years (start and end dates) or right away (upon fulfillment)
So the way it works is first the elements get formed, then they are clubbed together into 1 arrangement (contract) and then when diffrent performance obligations (elements) hit their trigger (create revenue plans on: item level) thats when the plan is formulated