to save an optimum content of cement, from 7.5 to 8 bags of 
cement to 6.6 bags of cement per CuM

to achieve economy and safety

To acheive best possible concrete with the ingredients 
available at particular location design mix is used.

to ensure required |Target Mean Strength by controlling the 
parameters of aggregate,sand and water accurately ....n 
also to design higher grade of concrete ...

....incase of nominal mis method(say),M15 means 15mpa 
comp.srength on 28 days using 1:2:4 proportions without 
considering various conditions of conareting 
materials ...the same will be rectified in design mix .

simply nominal mix is blind technique where as design mix 
is live n vibrant method of mix design in concrete 
technology to achieve anticipated TMS.