The proven Zacks Rank system focuses on earnings estimates and estimate revisions to find winning stocks. Nevertheless, we know that our readers all have their own perspectives, so we are always looking at the latest trends in value, growth, and momentum to find strong picks.Considering these trends, value investing is clearly one of the most preferred ways to find strong stocks in any type of market. Value investors use tried-and-true metrics and fundamental analysis to find companies that they believe are undervalued at their current share price levels.Zacks has developed the innovative Style Scores system to highlight stocks with specific traits. For example, value investors will be interested in stocks with great grades in the "Value" category. When paired with a high Zacks Rank, "A" grades in the Value category are among the strongest value stocks on the market today.Owens Corning (OC) is a stock many investors are watching right now. OC is currently sporting a Zacks Rank of #2 (Buy), as well as a Value grade of A. The stock is trading with a P/E ratio of 10.94, which compares to its industry's average of 16.57. Over the past year, OC's Forward P/E has been as high as 17.66 and as low as 10.94, with a median of 13.90.Investors will also notice that OC has a PEG ratio of 0.74. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. OC's PEG compares to its industry's average PEG of 1.38. Over the last 12 months, OC's PEG has been as high as 4.18 and as low as 0.73, with a median of 1.30.Value investors also love the P/S ratio, which is calculated by simply dividing a stock's price with the company's sales. Some people prefer this metric because sales are harder to manipulate on an income statement. This means it could be a truer performance indicator. OC has a P/S ratio of 1.28. This compares to its industry's average P/S of 1.96.Finally, our model also underscores that OC has a P/CF ratio of 7.87. This figure highlights a company's operating cash flow and can be used to find firms that are undervalued when considering their impressive cash outlook. This company's current P/CF looks solid when compared to its industry's average P/CF of 20.33. OC's P/CF has been as high as 9.36 and as low as 7.35, with a median of 8.45, all within the past year.These figures are just a handful of the metrics value investors tend to look at, but they help show that Owens Corning is likely being undervalued right now. Considering this, as well as the strength of its earnings outlook, OC feels like a great value stock at the moment. Zacks' Top Picks to Cash in on Artificial Intelligence In 2021, this world-changing technology is projected to generate $327.5 billion in revenue. Now Shark Tank star and billionaire investor Mark Cuban says AI will create "the world's first trillionaires." Zacks' urgent special report reveals 3 AI picks investors need to know about today.See 3 Artificial Intelligence Stocks With Extreme Upside Potential>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Owens Corning Inc (OC): Free Stock Analysis Report To read this article on Zacks.com click here.