Once a plan is agreed upon, it is treated as a commitment—not just a tentative intention that might change. Expect that deviating from plans requires explanation and justification. Casual changes, missed deadlines, or failure to deliver what was promised damage trust and credibility significantly.
If you need to change a plan, explain why the change is necessary and demonstrate that you understand the impact on others. Reliability—doing what you said you would do—is highly valued. Building a reputation for honoring commitments is essential for effective working relationships. Conversely, establishing a pattern of unreliability will undermine your standing, regardless of your other qualities.