What are the purposes of machine design?

In machine design, complex components their shapes, size and dimensions are easily designed on a paper.if you are not using this technique for making a product then you will face many problems.
suppose you are making a products and the products are incorrect dimensions then it will became fail and there will be a vast loss of the company.
for stopping the loss and time and others thing we use this technique.

Machine is made so as to lessen the burden of the consumers.
So why we have to design a new machine? Simple because everyday technology is changing.
The technology of today is not applicable for tomorrow.
So to keep  abreast with technology changes, we have to update machine's design.
Other things that we should consider is to make the machine as simple as it can be yet efficient and productive and less expensive.
The lesser the budget in making the machine the more profitable it becomes.
The more efficient it becomes more goods are produce.