Question: While reading this wikipedia [article](http://en.wikipedia.org/wiki/No_Silver_Bullet), Brookes has told that there is a difference between "good" designers and "great" designers. What is the difference between them? How can I decide if a designer is good or great?

Answer: 
If you want to know what Fred Brooks was saying in *No Silver Bullet* you should read [the paper itself](http://www.cs.nott.ac.uk/~cah/G51ISS/Documents/NoSilverBullet.html) and not a Wikipedia article about the paper. Brooks isn't specific as to the the precise difference but he nevertheless makes it clear that the distinction will be pretty easy to spot:

> 
> The differences are not minor--they are rather like the differences
>  between Salieri and Mozart. Study after study shows that the very best
>  designers produce structures that are faster, smaller, simpler,
>  cleaner, and produced with less effort... The differences between
>  the great and the average approach an order of magnitude.
> 
> 
>
Great designers can make 2 + 2 = 5. They change the art of the possible.