i want to analyze business case for small enterprise.how can i do it?

Answer 1

That's way too complex a question for this venue....

But, you'll need to look at-
acquisition costs
cost to service debt to acquire
existing business debt and cash on hand
estimated cash flows
existing inventory
estimated expenses - cost of goods, labor, taxes, etc.
threats - any liens or pending law suits, competition
potential growth

mix 'em all up and figure if you have a decent return/feasibility over your time horizon - e.g. 5-10 years.