In order to lead others, you need to be able to manage yourself. Whether you’re a manager or not, many business people fail at managing themselves when it comes to successfully locking in their schedule and actioning the tasks on it. There’s a multitude of reasons but the 2 biggest are:

The schedule’s unrealistic
You’re not committed to the schedule

The reasons for an unrealistic schedule are:

It’s a wish list - there’s too much packed into it. You’ve never processed this much work before so why will today or this week be any different? The wish list represents what you’d like to achieve but not what you will achieve.
No reactive time – even people who are very proactive at planning and scheduling have to react to as much as 20% of tasks they were unable to anticipate. They know there’ll be 20% of things that pop up requiring action but they’re not sure what the specific tasks will be. Imagine the impact of this if the reactive component of your role is 30%, 40% or even 50%.
Interruptions – most of us have to deal with some form of interruptions at work. If we’re working on a reasonably complex task then interruptions are detrimental to productivity because break our train of thought or concentration. There needs to be a considered approach to either manage or plan for interruptions.
Incorrect sequence – the order tasks are sequenced is wrong and they either can’t be completed at the expected time or they’re actioned too late. Either way, progress is negatively impacted.

The reasons you’re not committed to your schedule are:

Don’t believe it – you don’t believe you can complete everything that’s in the schedule so there’s no emotional connection to making it happen. You’re scheduling activities because you intuitively know you should be, but it’s not accompanied with the necessary levels of determination or conviction.
Prioritise others – while the schedule is in place you keep not actioning the tasks when they are due and prioritise other tasks over the top of it. This can be due to the tasks in the schedule being difficult to complete, they’re not the activities you like to do or they’re just the wrong tasks.
Keep rescheduling – when it comes time to action specific tasks you keep rescheduling them out to a later date. Technology makes this is so easy to do if your schedule exists in your email calendar but your schedule is basically useless if you keep doing this repeatedly.

The justification sometimes given for not actioning the schedule is due to the business environment. It’ll be some form of we’re too busy to plan effectively, our customers are so demanding that we need to respond urgently to stay competitive, my manager’s always changing priorities etc. All of these explanations can be somewhat partially true, but they’re also forms of excuses because the key to a successful schedule is to build it based on the environment. Otherwise, it will be ineffective.

Five things to do to improve the accuracy of your schedule are:

Weekly plan – at the minimum you need a weekly plan which factors in everything that needs to be completed for the upcoming week. Ideally, you will also have monthly goals or objectives which the weekly plan needs to reflect.
Proactive and reactive – the schedule needs to take into account the tasks you are scheduling to complete proactively plus the percentage of time you need to set aside for tasks you need to react to. (you may not know what these tasks are but each day or each week there’s an amount of time you spend in reactive mode on work that just needs to be done).
Meetings with self – schedule meetings with yourself in your calendar to complete your work. Then treat those meetings with the same level of importance and discipline you would in attending someone else’s meeting.
Reoccurring tasks – like putting the bins on the nature strip at home each week to be emptied there’ll be reoccurring tasks you can schedule at work. You’ll establish a routine when you frequently schedule and action your reoccurring tasks.
Commitment – the schedule won’t happen unless you commit to making it happen. It has to be realistic otherwise, you won’t commit to it and then you need to action it to build your belief. You’ll see value in doing it once you’re able to do this effectively

You get to choose how you work. How well you’re able to schedule determines whether you’ll be reactive, overcommitted or in control. Establish a rhythm to help you to consistently do your best work.