Current automation technology already can replace a large portion of what people do at work. That's not necessarily the same as replacing entire jobs, but it does mean the nature of certain positions will have to change.

Artificial intelligence and advanced robotics are capable of performing 45 percent of the activities humans are paid to do, according to an article in the November issue of consulting firm McKinsey & Company's McKinsey Quarterly.

"We're not sure which jobs will disappear per say, but almost every job will be transformed," says Michael Chui, a partner at the firm's business and economics research arm and one of the article's authors.

Even the roles of top executives will change. The authors estimate that 25 percent of activities performed by CEOs can be automated.

The report reflects interim findings in an ongoing study, and is based on current demonstrated technology. So, as automation technology advances, it will presumably be able to complete more human work activities.

As this trend unfolds, business owners will have to think about how they structure staff and decide whether to assign certain tasks to people or to technology. Here are three things Chui says executives should know about the future.

1. This is a real trend.

One activity where artificial intelligence lags behind humans is in the ability to understand language. But the technology is likely to catch up as research of natural language processing at universities and companies like Google continues. Chui says that once the cognitive capabilities of computers become roughly as adept as understanding language as humans, that single advancement will make it possible to automate an additional 13 percent of human work activities. "I think it's a very important and open question as to whether or not we're automating tasks or automating activities faster than we can create new jobs."

2. It affects all levels of jobs.

Increasingly sophisticated automation technologies can complete tasks requiring everything from fine motor skills and navigation of a physical space to a sense emotion and understanding of human language. "Even the most high-paid, high-skill jobs have a significant portion which can be automated," Chui says. Computers with cognitive capabilities can analyze financial and legal documents, for example.

3. Workplaces will need to restructure.

Chui compares automation to past major economic shifts, such as the Industrial Revolution. In part because of advances in manufacturing and in part because of other factors like labor organizing, the amount of time people generally spent working decreased dramatically. "Many jobs will be redefined rather than eliminated--at least in the short term," the authors write. There's room to discuss whether people should simply work less as more activities are automated, but there's also the chance that new jobs will emerge based on activities that can't be automated.