When you buy a mango, you can instantly evaluate its quality: the size, shape, ripeness, bruising, and the absence of visible decay. But only as you peel it or cut it using a knife, will you be able to see if the mango is really good and sweet. Even an extremely good looking fruit might taste sour or have a worm inside it.
The same concept applies to almost any product, be it a physical object or a piece of software. A tiny bug in the software might cost millions of dollars from investors. A small problem from a machine like cars and airplanes can cause thousands of lives. That’s why it’s important to always have quality assurance in place. This is to prevent and control these circumstances as much as possible.















