I am looking for similar words to task for a document on scheduling tasks in the context of a project. My goal would be to find words that would denote meanings for three things.
A word for a small atomic task of short duration that is to be done. This would be the fundamental unit. I'm thinking of: job, assignment.
A word to denote that this small task has been done. I'm thinking of: work.
A word for a larger task that is made of several small tasks, or even several tasks. I'm thinking of: task, labor.
As a non native English speaker, I am having troubles finding the exact meaning of all these words, and if my hierarchy, from small to large, is correct. Do native speaker have suggestions for other words?