You have too many distractions.

A recent survey by the research firm NFI Research found that 66 percent of senior executives and managers say e-mail is one of the biggest distractions in the workplace, followed by the crisis of the day and personal interruptions. According to the bosses surveyed, other workplace distractions include unexpected meetings, phone calls, Web surfing, socializing, instant messages and noise.
 
 
 

You don't have the resources you need.

A carpenter needs a hammer, an accountant needs an adding machine and most office workers need a computer. Nevertheless, new employees don't always have what they need to hit the ground running. (An employer once took a month to supply the software needed to do the job I was hired to do.) Likewise, if your co-workers aren't providing you with the data or assistance you need, your work may suffer. Before you blame your co-workers for not helping, consider if they are facing similar challenges getting their own work done.
 
 
 

You don't know what you’re doing.

FabJobs.com marketing director Clayton Warholm, an expert on workplace miscommunication, says there are two main reasons employees may not know enough to do the job. Either the assignment wasn't clearly stated by your employer (you don't know what to do) or you haven't been trained properly (you don't know how to do it). However, training will help only if you have the talent needed to do the job. In their book “First, Break All the Rules: What the World's Greatest Managers Do Differently,” Marcus Buckingham and Curt Coffman reported findings of interviews conducted by the Gallup Organization of more than 80,000 managers in over 400 companies. They found "the right talents, more than experience, more than brainpower and more than willpower alone, are the prerequisites for excellence in all roles" and, unlike skills and knowledge, "you cannot teach talent."
 
 
 

You have too much work.

Some people have so much work on their plates they couldn't do everything on their “to do” list even if they worked 24 hours a day, seven days a week. This may happen in any job, but particularly in fields facing a shortage of workers. The result: the frustration of trying one’s best to get everything done but not being able to do so.
 
 
 

You have poor time-management skills.

Workers with good time-management skills do what’s most important, while those with poor time-management skills work on what looks most fun or easy -- then frantically try to catch up on important work that has become urgent because the fun and easy work was done first. Hint: Work is rarely easy or fun if you end up missing deadlines and have to deal with an irate boss or customers.
 
 
 

You’re procrastinating.

Why put off until tomorrow what you can do today? Actually, you may have a good reason -- to avoid pain. When we procrastinate, it’s often because we’re afraid the job or the outcome will be unpleasant. For example, if you’re afraid of failure and fear that no matter what you do it won't be good enough; chances are you'll avoid doing anything. If your own need for perfection is holding you back, realize most employers and clients would prefer that you do an imperfect but good job, rather than not do the job at all.
 
 
 

You feel undervalued.

If you think you’re underpaid and unappreciated, chances are you aren’t giving 100 percent. Consciously or not, many employees try to “balance the scales” to ensure that what they give the employer is equal to what the employer gives them. According to Louis V. Imundo, author of “The Effective Supervisor's Handbook,” when the negatives of a job outweigh the positives, “employees may put less effort into their jobs, be absent more frequently, be careless or psychologically withdraw from work while being physically present.”
 
 
 

Your company’s priorities keep changing.

You are working on Project A when the boss says, “Drop everything and work on Project B.” When this happens, you may think you’re not getting any work done, but your employer may think otherwise. As the Myers-Briggs Type Indicator (the most widely used personality assessment) shows, some people are flexible and find it easy to change direction and exciting to start new projects, while others find it frustrating to not complete projects. If you are the latter and work in an industry where change is constant, you may want to consider a career change.
 
 
 

You’re burned out.

According to the Web site of the American Psychological Association, burnout is emotional exhaustion resulting from overwhelming stress at work. It may be caused by a hostile work environment or fears about job security, but it often results from long hours, stressful deadlines, high expectations, worrying about a project or taking on more work than you can handle -- in other words, working too hard. Because it can lead to serious conditions, such as depression and heart disease, you should seek professional help if you are experiencing burnout.
 
 
 

Your “reward” for completing the job will be more work.