Websites should be managed on the principle of self-service, and the key driver of self-service is time.

“The amount of time that consumers are spending waiting in lines at fast-food drive-thru windows is getting longer, not shorter, mostly due to the growing complexity of new products that the major fast-food chains are selling,” Bruce Horovitz writes in a study conducted for USA TODAY.

This is a classic and recurring problem that websites for large organizations face. Over time, as new stuff is added, websites become more complex and harder to navigate. Unless an active process is put in place to reduce this complexity customer satisfaction will drop as navigation complexity increases.

Fast food drive-thru accounts for 60% to 70% of the business of many of the major chains. So, it’s key to keep the customer happy.

The industry issue that's slowing down service: menu bloat,” Horovitz states. “Fast food's ongoing market-share battle is forcing big chains to roll out more premium and more complex products more often.”

Speed is not the only thing that matters to customers at a drive-thru. Order accuracy is also critical; very few people want to get the wrong burger quickly. Order accuracy is declining, according to the study. “Order accuracy for drive-thru meals for the industry was at 87.2% this year vs. 88.8% last year.”

Organizations feel driven to add new products and features so as to remain competitive. However, there is often an impact on parts of the established business by adding all this new stuff. In the drive-thru, times have risen from around 116 seconds in 2003 to over 180 seconds in 2013. At least the fast-food industry is measuring this. Many organizations don’t measure the impact of changes to the products or services they currently offer.

When we are adding we may indeed be adding benefits, but we are also quite possibly adding complexity. The simplicity of a menu on a website is just as important as the simplicity of a menu at a drive-thru. In fact, we have found over the years that the number one cause of task failure on websites is menu complexity.

The larger the menu, the longer it takes to make a decision and the higher the chances that that decision will be wrong. But an even bigger factor than menu size is overlapping or confusing menu choices. Menu options such as “Resources,” “Tools,” “Knowledge Base,” “FAQs,” “Quick Links,” etc. make it very difficult to successfully navigate a website.

The best way to identify website menu complexity is to regularly test top tasks with real customers. Track success rates and time on task. Also, track accuracy, failure of which we call "disaster." (This is where they think they’ve got the right answer but it’s wrong.)

Track these metrics on a six-monthly basis, or whenever you add lots of new things to the website. Make changes that increase success rates for the top tasks, and reduce the time to complete the task.

Before you add anything to a website, always ask: How will this impact what is already there?