The act of changing or making changes, and arranging (arrangement) of something.
The root word of change with the suffix of "ment" added on to create the combination of an entity that better helps explain what we are wishing to say, but faster.
Friend: "Yo bro, you wanna come to the Susan Boyle concert tomorrow?"
Me: "If I did, I would need to make some changments to my current schedule; however, I'd rather take a shit in the bathtub."
"I will need to make some changments to the floor plan, but afterward the layout should be fine."