Time is limited to how many hours there are in a day and some things cannot be put off until tomorrow. As a student you will be given time critical tasks that must be completed by a certain time and date. Late is no good and neither is unfinished work going to give you good results.
For students time management is a crucial skill to be learned and understood. There are so many distractions in student life that it is easy to forget all about the work until it is getting to be too late to complete it in time. Planning is crucial and setting a time period to complete the work in is vital to avoid being overwhelmed with the task.
With a plan of work you should have allowed a reasonable time to complete any part of that work and have the finsihed material ready to be delivered on time with the knowledge that you have done a decent job of it. Without a plan you may well end up rushing to complete the work when your friends are finished and relaxing.
It may sound boring but an organized schedule helps you and actually keeps you focused on the important tasks. It should also enable you to spend a little more time on some parts of your work if you need to without this meaning that some work doesn't ever seem to get finished.
It is important that you plan properly and schedule your work. A vague plan will not be as effective or helpful. Proper planning will aloow leeway so that if one part of your work takes longer than expected you can adapt the plan and get back on schedule to complete the work by the deadline.