Sometimes, no matter how hard you try to concentrate, the office is simply too distracting. And if you're working on a tight deadline or an important project that you have to get just right, that adds to the pressure. In fact, even if your office is relatively quiet and sedate on a day when you're grappling with said deadline or project, you might suddenly find even minor noises or movements highly distracting.
Some open plan offices do incorporate private offices (or quiet rooms) that people can use, so escaping there could be an alternative. However, if these are often booked, or feature glass, fishbowl-type walls, this may not be an adequate solution.
That's when it helps to have private zones. Ideally, private zones are secluded spots equipped with a desk and chair, available to employees temporarily. If your office doesn't contain such a setup, you can create one on your own by moving desks, couches and the like into your desired setup. If nothing else, grab your work materials and a chair, then sit facing a corner.