What life cycle should I think about buy & hold rental properties

[Vincent Chen]

I am in my research phase of my REI investment and I know I must understand the deal and cash flow analysis.

But I have the questions regarding what is the life cycle should I think about?The numbers might be good first year or short term,but if I need to hold this property for 3~4 years,how should I run the numbers for that?

And what is the trigger for selling rental properties?Need cash for new investment or number start not working?

How do experts or seasoned investors figure out whether the rental properties buy or not?