The concept of reliability in professional relationships involves observing simple actions, such as how quickly someone returns a phone call or whether they honor their commitments to attend meetings. These behaviors serve as indicators of a person's dependability and trustworthiness in both personal and business interactions.

In his book "The Trusted Advisor," David H. Maister emphasizes that consistent completion of tasks, like to-do lists, further reinforces an individual's reliability. The way people manage their time and commitments reflects their professional integrity and can significantly influence the trust others place in them.