Payback period highlights in years, the time taken for the investment to payback itself, ie to breakeven. Beyond Payback period, businesses can start accruing profits, and it is important to know how soon this time can start.
As the name indicates, Payback period = Initial Investment/ Annual Cash flow.
As a means of comparison, higher the payback period, less lucrative the investment.
The biggest advantage of this metric is the ease of its calculation, and hence it comes in very handy to compare various options, in our case, project selection.
On the other hand, the biggest disadvantage of this method is that it ignores time value of money. Simply put 100 units of currency are worth more today than in future. This can be easily accounted in NPV thereby making it a better metric to use.