Scrum is a framework that implements an empirical process. In general, empiricism is a principle that states that to obtain knowledge people should depend on practice and experiments, rather than on theories. In fact, thanks to this process, progress is based on observations of reality and not on imaginary plans.
There are three pillars that support every implementation of Scrum:
Transparency requires that crucial aspects of the process have to be visible to those who are responsible for the outcome. To accomplish this goal it is important that these aspects are being defined by a common standard. This will help observers to clearly understand the critical aspects.
Basically, all people involved in the process are transparent when dealings with others. It is important to build a sense of trust among the people of the team. So that, they will have the courage to keep each other informed of good and bad news. As a result, each member of the team will strive to collaborate for reaching the predefined objective.
The Scrum Team frequently inspects the artifacts and progress toward a Sprint Goal. During inspection the Scrum Team is able to detect undesirable variances.
In addition, the team can inspect the product, processes, people aspects, practices, and continuous improvements. Usually, at the end of each Sprint the Scrum team shows the product to the stakeholders in order to obtain precious feedback. In case stakeholders want to change the requirements during inspection, the Scrum team collaborates with them to clarify the requirements and analyse the new requests.
If the Scrum team determines that one or more aspects of a process go beyond admissible limits the process have to be adjusted. In fact, it is important to act this way in order to avoid that the final product will be unacceptable. In this case, it is vital to make adjustments as soon as possible in order to minimize further deviation.
Adaptation is about continuous improvement, the ability to adapt based on the results of the inspection it is key for the success of the Scrum implementation.