The old saying that familiarity breeds contempt may ring true in today’s popular open-plan office spaces where proximity is taking a bite out of productivity.

A colleague who drops by to chat can disrupt your workflow, and experts say this makes you more prone to errors, robs you of important to-do list execution time and leaves you confronting the dismal reality that your work at the office is never really done.

While open-plan office spaces are designed to spur collaboration, it has its downside, experts say. If you want to ace your performance reviews and chart an upwardly-mobile career path, you are going to have to learn how to tactfully fend off those uninvited interruptions.

 “Even small interruptions are costly,” says Erik Altmann, a psychology professor at Michigan State University and lead author of a study published earlier this year about how momentary interruptions can derail train of thought. When the thought process is broken on a sequentially dependent task for as little as 4.4 seconds, error rates triple.

Time loss compounds the problem of never feeling caught up at work.  Knowledge workers require large chunks of time to complete work, says Tom DeMarco, co-author with Timothy Lister of Peopleware. “An interrupt includes the time of the interrupt plus an additional 20-to-25 minutes to get back into the groove-state psychologists call flow.”

Low cubicle walls can lead to more disruptions, says ProductivityPro’s Laura Stack, author of What to Do When There’s Too Much to Do. The disturbance can be as simple as: You’re working, someone flashes by and you look up. ”Eye contact alone can cause drive-by distractions.” The randomness and ad hoc permissiveness of it all can be disruptive. 

Stack recommends bolstering your own self-control by situating your desk so that your back is turned to the traffic area. You can also block your peripheral view with a plant or your monitor. Another subtle signal: Put a clock on the wall opposite your cubicle entrance. The time reminder will be the first thing unwanted visitors see when they enter your space.

A coat or some files on your visitor chair is also a deterrent, claims Productivity Experts founder Cathy Sexton, or don’t even have a chair.

Get Creative to Stay Productive

Sexton’s client, Perkins Lumber Company’s Cindy Pratt, says she stands up to receive visitors. “Coworkers are less likely to feel at home.”  If the subtle cue isn’t heeded, Pratt starts shuffling papers, signaling her need to get back to work.

Experts dub ear buds and big headphones generally accepted office sound blockers, but some workers have found more creative alternatives. Several years ago, Eva Milko, senior director of global procurement at Molson Coors, invited Stack to conduct a time management in-service after identifying a problem of employees “dropping in and hanging out.”

“People just didn’t know how to say ‘go away,’” says Milko. The group discussion sparked a solution appropriate for the relaxed culture at Molson Coors: workers hung bright-colored southwestern style curtains on cubicle entrances, with closed curtains signaling do not disturb. It worked very effectively till the company lowered cubicle walls.

“Now I’m not suggesting Citibank or Chase hang curtains in their offices,” jokes Milko. Solutions and cultures have to jibe. Still, she knows of one Colorado employer that allows employees to hang small flags on cubicle openings. When the flag stands upright, coworkers know an employee cannot be interrupted. And, CubeGuard, she notes, provides yellow “crime-scene-like” tape. A tape across a cubicle entrance cues colleagues: Do not disturb.

Technology, often targeted as an interruption, can also work as a benefit. For example, CanFocus silences digital interruptions and deters coworker distractions through a light-up device, MyFocus, that lights red when you need to be on-task and green when you’re able to talk. It’s a less threatening and more impactful strategy than snapping at a coworker, says CanFocus CEO Paul Chipperton.

RescueTime helps people learn how they’re spending their work day. Metrics provide the perfect opportunity to identify interruptions, says CEO Joe Hruska. Employees then can minimize distractions by setting alerts that warn of exceeded activity time limits, and alternately reward employees for staying within their goals.

Both systems enable users to identify their prime productivity zones. If you’re like Chipperton, you’re super-productive between 8 a.m. and 2:30 p.m. Perhaps you’re typically overloaded with meetings during that time period, he says. You can modulate your behavior and think twice about going to a meeting or more appropriately engineer a reschedule by talking to your boss. 

If you find your work flow constantly being interrupted by your co-workers, experts offer the following tips to make sure you get your to-list completed:

Apply the 80-20 rule. Current research says only 20% of interruptions are important, says Sexton. Figure out what they are and work with your team to apply rules that establish appropriate permissions and barriers.

Do unto others. Rules are reciprocal, reminds Altmann. Resist the impulse to poke your head into a colleague’s work space to say “hi.”

Hang with a like-minded crowd. Sit with workers who share your job function, says DeMarco. A writer near a sales person will evolve into a disaster.

Manage up. Managers can be a source of continued interruptions, says DeMarco, and Stack recommends the following: Look at your watch and say, “’I’ll be heads-down on your project. Anything you need from me in the next hour?’” The can do/will do attitude can lead to a more comprehensive discussion in which you guide your manager to help you reprioritize your goals.

Push the envelope. Be clear, comprehensive and solution-oriented in a productivity discussion with your manager. “Curtains and flags are simple examples of a bigger issue,” says Milko. “It’s one thing to write about mission and vision, but when you walk through the office can you actually feel it?”