In theory anything is possible when designing software. In theory, theory and practice are the same. In practice I have never seen a succesful idea that redesigned the entire product.
When having limited time/budget (which in fact is just about always) you need to realize that building something that has never been built before will take up an incredible amount of time, even when its something very small.
The movie Flash of Genius demonstrates this nicely; Robert Kearns invents the interval setting of a windscreen wiper. None of the elements were invented by him (not the wiper, not the motor, not any of the elements) but combined they become something that millions of people now benefit from every day.
If you can re-use something that is already there, think twice before making it yourself.