Commitments defines Values !!!
How Valuable Human Being You Are ? Is not because of how much money you hold, but because of how you handle your commitments or your responsibilities.
If you have given your words, then you should be committed, if not then, you will always fail your commitments.
Now, why does it happen that you do not inform the person in case you find yourself that you will not be able to fulfil the commitment?These things happens because of two factors1. Ignorance2. Fear
Ignorance, because the other person do not hold any importance as such, as per your opinion.
If ignorance is a case, you need to go through this link and read this article.
And the only way you can go ahead to make your commitments fulfilled is only by overcoming these two problems.
And following this, you will notice that your commitments will start taking its shape.