Can I just focus on one criteria to analyze stocks quickly?

Thanks for your question.
While each of the individual parts or formulas used in analyzing stocks are considered to be important, they are somewhat useless and can even be dangerous if you focus too much weight on any one of them. Often times, common sense is more valuable for investing than using any individual analysis criterion.
In a nutshell, you’ll want to use some of the most practical analysis criteria together (ROE, ROIC, PE Ratio, Gross Margin Percent, etc.) and compare all stocks in a similar way to find the cream of the crop. From this group of stocks, you will do further analysis (quantitative and qualitative) and most importantly, use common sense to figure out if you should personally invest in this stock or that stock.
I really recommend getting an overall understanding of the process first, then tackling the individual criterion one-by-one, so that you can become a good overall investor and not get stuck into the trap of analysis paralysis.
I recommend two things. Start by reading how I came up with the process of using the BTMA Stock Analyzer to follow Graham’s and Buffett’s strategies of value investing:
http://www.beatthemarketanalyzer.com/blog/find-stocks-like-warren-buffett/
I also highly recommend reading: Buffettology by Mary Buffett and The Warren Buffett Way by Robert G. Hagstrom.
I don’t have enough good things to say about how valuable these books are for stock investors.
Especially Buffettology will basically lay out the foundation of why I chose to include the specific criteria that I did in the BTMA Stock Analyzer.
I hope this info is helpful for you.
-Grant
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