Investors with an interest in Engineering - R and D Services stocks have likely encountered both Sterling Infrastructure (STRL) and Aecom Technology (ACM). But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.

Everyone has their own methods for finding great value opportunities, but our model includes pairing an impressive grade in the Value category of our Style Scores system with a strong Zacks Rank. The Zacks Rank is a proven strategy that targets companies with positive earnings estimate revision trends, while our Style Scores work to grade companies based on specific traits.

Sterling Infrastructure and Aecom Technology are sporting Zacks Ranks of #1 (Strong Buy) and #2 (Buy), respectively, right now. The Zacks Rank favors stocks that have recently seen positive revisions to their earnings estimates, so investors should rest assured that STRL has an improving earnings outlook. However, value investors will care about much more than just this.

Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.

Our Value category grades stocks based on a number of key metrics, including the tried-and-true P/E ratio, the P/S ratio, earnings yield, and cash flow per share, as well as a variety of other fundamentals that value investors frequently use.

STRL currently has a forward P/E ratio of 14.09, while ACM has a forward P/E of 18.45. We also note that STRL has a PEG ratio of 0.94. 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. ACM currently has a PEG ratio of 1.58.

Another notable valuation metric for STRL is its P/B ratio of 4.30. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. For comparison, ACM has a P/B of 5.20.

These are just a few of the metrics contributing to STRL's Value grade of B and ACM's Value grade of C.

STRL has seen stronger estimate revision activity and sports more attractive valuation metrics than ACM, so it seems like value investors will conclude that STRL is the superior option right now.

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This article originally published on Zacks Investment Research (zacks.com).

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