Cogitus Interruptus is the disease of the modern workplace. Its symptoms are familiar to any executive: the inability to complete a thought or a task without losing focus under the onslaught of relentless interruptions. It results in a lack of efficiency, a loss of time to solve problems, to think strategically, to plan, to dream – to get your company from here to there. But there’s hope: there are techniques to help you regain the opportunity to think without interruption.

It’s no surprise that our ability to focus on a single task without interruption is waning. What is a surprise is the extent to which interruptions define our workdays. In a survey of 1000 senior executives, technology research firm Basex found that knowledge workers lose about two hours per day due to unnecessary interruptions such as instant messaging, spam e-mail, telephone calls and the Web. Of course, some of the damage is self-inflicted: more than 60% of the respondents read email immediately or nearly immediately.

Gloria Mark, a researcher at UC Irvine, found a similar situation. Each employee she studied spent only 11 minutes on any given project before being interrupted. Moreover, it would take 25 minutes on average to return to that task.

To some extent, an increase in interruptions is an inevitable result of today’s larger, more complex organizations. Managing sprawling enterprises requires more team interactions, and dotted line relationships in matrix structures abound. The pervasiveness, ease, and zero cost of email, IM, and SMS has exacerbated the situation by encouraging communication, even when it’s not valuable.

But in fact, there is a real cost to this communication; it’s just not borne by the sender. It’s borne by the recipient. Mary Czerwinski, at Microsoft Research Labs, found that 40% of the time, workers wander off in a new direction when an interruption ends, distracted by the technological equivalent of shiny objects. As the New York Times put it,

The central danger of interruptions, Czerwinski realized, is not really the interruption at all. It is the havoc they wreak with our short-term memory: "What the heck was I just doing?"

But even when people remember what they’re supposed to do, they’re less efficient in completing those tasks. But even when people remember what they’re supposed to do, they’re less efficient in completing those tasks. David E. Meyer, a cognitive scientist and director of the Brain, Cognition and Action Laboratory at the University of Michigan, says,

Multitasking is going to slow you down, increasing the chances of mistakes. Disruptions and interruptions are a bad deal from the standpoint of our ability to process information.

And René Marois, a neuroscientist and director of the Human Information Processing Laboratory at Vanderbilt University points out that for all of the hundred billion neurons in the brain, “a core limitation is an inability to concentrate on two things at once.”

The University of Michigan and the FAA found that people who switch between different types of tasks – say, email and spreadsheets, or drafting a contract and talking to a colleague – lose 20-40% of their efficiency. Just as there’s changeover time for machines on a production line, the human brain loses time in changing over from one type of task to another. Peter Drucker saw this forty years ago: in The Effective Executive, he wrote,

To be effective, every knowledge worker, and especially every executive, therefore needs to be able to dispose of time in fairly large chunks. To have dribs and drabs of time at his disposal will not be sufficient even if the total is an impressive number of hours.

On a less quantifiable – but no less important – note, the interruptions prevent executives from achieving what psychologist Mihály Csíkszentmihályi describes as the “flow” of work. In his book, Flow: The Psychology of Optimal Experience, he theorizes that people are happiest when they’re in a state of flow (or “in the zone”), totally immersed in a task that is fulfilling and intrinsically rewarding. One of the prerequisites for getting in the “flow,” of course, is the ability to focus and concentrate on the task at hand – which is impossible in an environment of constant interruptions.

I believe that at their core, talented, motivated people yearn for uninterrupted periods of work when they can feel both productive and fulfilled. I know the president of a mid-sized residential construction firm who goes to the office every Saturday for three hours to design new homes; only then can he find such a large block of time for his work, and only then does he “get in the groove.” Similarly, partners at a large law firm I’ve consulted to regularly work at home at night and on weekends for the same reason: it’s the only time when they “can get things done.”

So what’s the solution? If you’re Sandy Weill or Warren Buffet, you just don’t use email – and although that doesn’t eliminate interruptions (there are still phone calls and knocks on the door, after all), it does reduce them. But that’s not a practical option for most people. For those who can’t unilaterally dictate modes of communication, here are some ideas:

1. Group similar tasks into blocks of activities in order to reduce the time lost to switchover. Do your budgets, your drawing, your contract reviews, etc. at one time rather than switching between them.

2. Establish meeting “corridors” – essentially office hours when you’re available to meet with colleagues. Obviously, during emergencies people will disturb you, but this will reduce the non-urgent interruptions. A company I know has a totally open floor plan. They don't have any offices, and the cube walls are low – about chest height – so there's no privacy. They've found a simple solution: each person has made two paper signs. A green sign (made with green highlighter) says "open," which means they're available to talk. A red sign has a time written on it – in other words, "do not disturb until ___ o'clock." Even better, set up standard check-in periods during the day for the people with whom you interact the most: when they know they’ll get to see you for 10 minutes each morning and afternoon, they’ll be more willing to wait.

3. Turn off email alerts to reduce distractions. Even if you don’t respond to an email immediately, the very act of reading (or hearing) the alert fractures your concentration. Learn to deal with email in blocks – twice a day, four times a day, once an hour – whatever is the appropriate interval for you and your firm.

4. Set “service level agreements” that support your work. With email in particular, there’s an assumption that because a message can be sent immediately, it must be answered immediately. And in point of fact, we’ve trained people to expect instantaneous response. But more often than not, people don’t really need an immediate answer; they need a predictable response – say, within a few hours or within the day. To address emergencies effectively, set up a “white list” for certain people, and an email rule that notifies you when those people send you a message. Or better yet, have people use the phone for urgent issues. After all, if the issue is that critical and time-sensitive, asynchronous communication tools are not the best option.

Making these changes can be disruptive, so it’s important to inform clients and coworkers in advance. And while these new ways of working may seem odd and cause friction at first, in the long run, they’ll make you – and your team – more productive.