Before a plane takes off it needs to gain a certain speed. To gain that speed the runway has to be a certain length. If the runway is too short the plane will overrun it. Each type of plane has a specific minimum runway length to be able to lift off.
Now when you start a project you need to know your runway. This is the minimum amount of money, effort and time you need to reach breakeven point. At breakeven you become profitable. You don’t want to start a project and then realise that you need a much longer runway. Knowing your runway allows you to mobilize the necessary resources ahead of take off.
This concept of runway applies to many areas of life. A good marriage takes a certain amount of time and effort to build. Successful careers need time and effort to build. Famous brands took a certain amount of time, effort and money to create. Great nations took centuries to build.
So what is your runway?