Indivisible and divisible

Hi, What's the difference between indivisible and divisible? Please, can i also confirm you my understanding as well? From my understanding: Indivisible method is to ensures that the project is close to the capital constraint. To make it Divisible, you have to work out the NPV Optimal investment programme that is exactly within the capital constraint. For instance: Initial cost NPV PI Ranking Proj 1 40 4 1.1 3 Proj 2 30 5 1.17 1 Proj 3 50 6 1.12 2 Proj 4 60 5 1.08 4 So Divisible, after calculating the PI (Profitability Index) and ranking them, i would have to work out how much % that the company will invest in each project from the rankings? Whereas, for Indivisible, I would just need to add up the initial cost and npv based on the ranking, ensure that it does not go over 100, as below 100 capital strain is fine? Thank you.