Why failure is necessary ?

I will tell you one small story which clearly reflects the answer of this question.

Unilever had a problem. They were manufacturing detergent at their factory near Liverpool, in the northwest of England, in the usual way — indeed, the way detergent is still made today. Boiling hot chemicals are forced through a nozzle at super-high levels of pressure and speed out of the other side; as the pressure drops they disperse into vapor and powder.

the problem for Unilever was that the nozzles didn’t work smoothly. To quote Steve Jones, who briefly worked at the Liverpool soap factory in the 1970s before going on to become one of the world’s most influential evolutionary biologists, they kept clogging up.1 “The nozzles were a damn nuisance,” he has said. “They were inefficient, kept blocking and made detergent grains of different sizes.”

This was a major problem for the company, not just because of maintenance and lost time, but also in terms of the quality of the product. They needed to come up with a superior nozzle. Fast.

Unilever, even back then, was a rich company, so it could afford the brightest and best. These were not just ordinary mathematicians, but experts in high-pressure systems, fluid dynamics, and other aspects of chemical analysis. They had special grounding in the physics of “phase transition”: the processes governing the transformation of matter from one state (liquid) to another (gas or solid).

These mathematicians were what we today might call “intelligent designers.” These are the kind of people we generally turn to when we need to solve problems, whether business, technical, or political: get the right people, with the right training, to come up with the optimal plan

You have probably guessed what is coming: it didn’t work. It kept blocking. The powder granularity remained inconsistent. It was inefficient.

Now comes the interesting part…

Almost in desperation, Unilever turned to its team of biologists. These people had little understanding of fluid dynamics. They would not have known a phase transition if it had jumped up and bitten them. But they had something more valuable: a profound understanding of the relationship between failure and success.
They took ten copies of the nozzle and applied small changes to each one, and then subjected them to failure by testing them. “Some nozzles were longer, some shorter some had a bigger or smaller hole, maybe a few grooves on the inside,” Jones says. “But one of them improved a very small amount on the original, perhaps by just one or two percent.”
They then took the “winning” nozzle and created ten slightly different copies, and repeated the process. They then repeated it again, and again. After 45 generations and 449 ‘failures,’ they had a nozzle that was outstanding. It worked “many times better than the original.”

See friends. It is really hard to become successful without excepting failures so be ready for and embrace it because the person who embraces failure quickly and then learn from has a better chance of becoming successful in his life. So don’t be scared of failure in fact it is your biggest opportunity to success.you just have to learn from it.