Agile uses empiricism in order to adjust to the dynamic requirements of the customer. Empiricism is the act of addressing and making decisions based on what is really EXPERIENCED. The empirical strategy works in a fact-based, experience-based, and evidence-based manner, and development is based on MEASUREMENTS of truth or reality and not fictitious plans. 

The three pillars that SUPPORT the implementation of empirical process control are  

• Transparency: Transparency can be achieved by tools such as Product Backlog, Task Boards, Burndown charts, Daily Stand-ups, Retrospectives, Definition of Done, Sprint Reviews, etc. It allows visibility with regards to the progress of work and team 
• Inspection: The artifacts must be regularly examined and progress towards a purpose or goal should be detected to avoid undesirable variances. 
• Adaptation: It always embraces and Adapts VARIATIONS or changes to constantly improve. Adaptation implies to have changes that does not work or what could work better.