This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Sumit Bhoyar wrote:If nothing is mentioned about concurrent users in requirement then is it safe to completely ignore number of concurrent users and in a way capacity planning?
No. You thought of it. It is a legitimate concern. However since the assignment didn't specify, you can assume anything you want. I had some assumptions like "I assume I asked the customer and he said XXX".