When to Consider Private Equity

The decision to take on private equity is a difficult decision for most business owners. Why bother with the effort and risk?
There are a variety of reasons but in my career working with business owners, I have found it generally comes down to these four reasons to look at private equity partners:
1) The founders' increased need to shore up their personal financial security, 
2) To finance further growth, or  
3) To help prepare a company for a future IPO within 3 years 
4) To prepare for partial or full sale within the next 5 years.