a synonym for "a project", "an enterprise"

I’m looking for a fairly formal word describing a project (especially business one) that is not in an advanced state of realization and is not specified partcularly. The following words have come up to my mind: undertaking, initiative, and I’m not sure about intent. Thank you for help!

You can also try “effort.” Since it sounds so tentative, you might also consider “plan” and “proposal.”

Thanks! And what about “undertaking” and “initiative”? Can I use them as synonyms for an economic activity?

Yes, you can.