This core concept refers to how change is managed when proposed changes to requirements and designs are evaluated during an initiative.

Let's look at an example to bring this concept of change to life:

One of the stakeholders in the Customer Services area approaches you as the business analyst to mention to you that he has changed what he wants in terms of the way that customers request a review of their electricity supply charges. He now wants the customer to be able to complete the full request online via the Customer Portal instead of only initiating the request online as per the documented requirements. In response to this, you tell the stakeholder that there is a formal process for requesting changes to approved requirements such as this one and that you will guide him through what this change request process entails. You then help this stakeholder to formulate the exact required change to the existing requirements using the change request template. Once the change request is submitted, you inform the stakeholder that the Change Control Board will review the request. You also promise to keep the stakeholder informed regarding the progress of his change request. 

This example illustrates how the core concept of change is implemented in the Requirements Life Cycle Management knowledge area.