Search engines use a variety of factors to determine the website/webpage rank (and the algorithms used to determine position vary with great regularity), so it's really important for brands to have processes in place and a willingness to adhere to the very well-established best practices.
You might actually be surprised, however, how few enterprises/brands actually commit to making SEO a worthwhile initiative. Most are content to simply do the absolute bare minimum, looking at SEO as something to be done once and after a website is built, instead of approaching it as the foundation of success in the digital landscape today.
Fortunately, there are several basic principles that any SEO professional can (and should) implement and abide by to ensure that their website doesn't suffer in terms of poor rankings - now or in the future.
:: Leverage Short, Descriptive Naming :: Most Web content management systems and ecommerce platforms provide some means to customize the URL structure of a site, from folders to actual page names. If you're serious about success with SEO it is necessary to gain control of this element. While URL naming is likely no longer a major influencer of higher ranking results, there's more to page and site naming than meets the eye. Search engine optimization is also very much about optimizing the customer's experience, not exclusively optimizing for higher ranking on the search results pages. Web page and file/folder naming should be analyzed as it can include primary or secondary keyword and key phrase references that may indicate a page's relevance to the user. It's important, therefore, that important pages on your website are named accordingly as when they are shared they will carry influence over other prospective visitors. Do a site wide scan of your website and identify those pages which aren't illustrating to users what those assets are about.
:: Breadth and Depth of Information :: Continuing the focus on user experience, know that the search engines want their users to find information that is useful to their query. It's really one of the most important things your digital marketing team can expend its energy upon. For this reason, seriously consider re-optimizing older pages of your website. When was the last time you went back to pages that were created 2-3 years ago (or even longer) and took the time to update out-of-date material or modify some aspect of the content that has changed in some way? Once a page has been indexed by the search engines, they will crawl that page again (and again) so it is your responsibility to ensure that pages either receiving a substantial amount of traffic but which are out of date, or pages which no longer receive traffic but should, are carefully re-crafted or re-tooled to ensure that they meet the expectations of users.
:: Linking Strategically Cross Site :: If yours is a website that focuses its attention on a specific area of attention (a particular subject matter for example), chances are high that there are numerous opportunities to organize content into topical clusters. These clusters of information are useful in two regards; first, they serve as additional content that can be used to help users more fully experience your content, your website, your business, and its brand and products. Second, by linking pages together in an organized, hierarchical manner, you're giving the search engines an indication of what content and what pages on your website is most important.
Linking strategically, re-developing content and improving naming conventions by themselves aren't enough however to sustain your enterprise and help your brand optimize its search presence - but it's a really good start. What's most important is that these approaches and tactics are practiced rigorously each and every day by your digital marketing department. These methods are proven to work in creating a better user experience (which, as was mentioned before, is a powerful tool to - although an indirect one - for optimizing your presence on the search engines).