A company the size of 3M (MMM 0.57%) is incredibly complex, but there are a few keys that investors can watch to see signs of trouble. In our premium report on the stock I've highlighted the keys to watch along with a detailed look at the company's opportunity and risks. 

Here is an excerpt from this in-depth report; it is just a small peak into what is covered in the full report:

The Three Areas You MUST Watch
In a company the size of 3M there are a million factors to watch for, but these three numbers best sum up the company's performance:

    1. Organic growth: The best measure of 3M's ability to innovate and take share in new markets is the company's organic growth. In the third quarter of 2012 the company's sales declined but organic growth was 2.2%, which is still progress. If 3M is going to become more than a dividend stock it will have to increase organic growth to mid-single digits or even double digits. This would expand the P/E ratio and generate strong returns for shareholders.
    2. Operating margins: 3M has mastered the art of commanding high margins for commodity products, but this tends to bring a lot of competition into the market. 3M is able to stave off much of this competition with superior manufacturing capabilities and innovative processes, but if 3M doesn't stay on its toes then the competition will move in quickly. Keep an eye on operating margins, which should exceed 20%, for signs of deterioration in the business.
    3. Payout ratio: If 3M isn't going to grow the top line at double-digit rates then it will have to maintain a steady and growing dividend to please investors. In the third quarter of 2012 the company paid out 41% of free cash flow in the form of dividends, but it also spent 33% of free cash flow on share repurchases. These ratios are not a problem currently but investors should keep an eye on them to make sure the dividend payout will continue to grow.

If organic growth picks up even slightly, operating margins remain high, and 3M can maintain a reasonable payout ratio, the stock will provide a steady return for shareholders.