Investors interested in Consulting Services stocks are likely familiar with CRA International (CRAI) and Accenture (ACN). But which of these two companies is the best option for those looking for undervalued stocks? Let's take a closer look.The best way to find great value stocks is to pair a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.CRA International and Accenture are sporting Zacks Ranks of #2 (Buy) and #4 (Sell), respectively, right now. The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that CRAI has an improving earnings outlook. But this is just one piece of the puzzle for value investors.Value investors analyze a variety of traditional, tried-and-true metrics to help find companies that they believe are undervalued at their current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.CRAI currently has a forward P/E ratio of 8.98, while ACN has a forward P/E of 20.64. We also note that CRAI has a PEG ratio of 0.69. This metric is used similarly to the famous P/E ratio, but the PEG ratio also takes into account the stock's expected earnings growth rate. ACN currently has a PEG ratio of 2.Another notable valuation metric for CRAI is its P/B ratio of 1.17. Investors use the P/B ratio to look at a stock's market value versus its book value, which is defined as total assets minus total liabilities. By comparison, ACN has a P/B of 6.26.Based on these metrics and many more, CRAI holds a Value grade of A, while ACN has a Value grade of D.CRAI sticks out from ACN in both our Zacks Rank and Style Scores models, so value investors will likely feel that CRAI is the better option right now.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 Charles River Associates (CRAI): Free Stock Analysis Report Accenture PLC (ACN): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research