When you have a lot to do, prioritization becomes more important. When you have more to do than you have time for, prioritization is extremely important. When you have very little to do, any prioritization scheme works pretty well.
Doing tasks in order works fine when you have a small number of tasks. Since older items bubble up to the top of the list, they will tend to get done. This is a good scheme to use when you are otherwise at a loss for what to do. Doing the first task on your list is better than spending time fretting about which task to do first.
Prioritizing based on customer expectation means first doing the tasks that customers expect will be done quickly. Customers expect small requests to be done quickly if the problem will delay their larger projects. You spend the same amount of time working and have more satisfied customers when you prioritize this way.
When deciding which projects should have higher priority, base the decision on impact. A high-impact project that requires a large effort to complete will benefit you more than a low-impact project that is easy to achieve.
Requests from your boss should have special priority. Your boss's requests often have dependencies that you are unaware of. Don't be the reason his larger project is delayed!
To manage your boss, you must do three things: make sure your boss knows your career goals, use upward delegation only when it leverages his authority, and understand his goals and be part of accomplishing them. When you do these three things, you are in better sync with your boss, and he becomes more flexible with your requests because he knows that you have his best interest in mind.
