Projects are usually encountered with a constant that is consistent. I like to call it a constant delta, oxymoron intended. For the noobs, this is frown upon and recorded as issues. Instead, a positive mindset is encouraged to embrace these delta. You will notice that Agile is unable to exist in organisational context due to traditional structures, policies and roles.

Another View of Delta
Delta management is rarely emphasised because traditional project management focus on fixing scope, time and cost. Variables are deemed to be risks with negative impacts for projects. This view of delta does not change until the recent explosion of Cloud technologies with Agile. The Agile project is a 180 degree view to regard change as constant. This paradigm shift to handle changes instead of freezing scope brings upon a new view of Delta.
Human Avoid Delta
Unfortunately, organisational view remains entrenched in fixed scope. The slow rate of change is consistent with human reluctance and avoidance to change. There are no revision of organisation policies or financial tools to manage delta. This lack of knowledge and uptake will persist for the next 5 years until all applications moved fully to Cloud.
Agile is the best technique to handle constant delta in projects. For many Agile practitioners, we are frustrated by the lack of delta management in the organisations. The gap between Agile and constant will remain unless there are more efforts to focus on how to incorporate delta within organisations.