Checkland's Soft System Thinking introduces three important changes in how we approach systems. First, it shifts from general to applied system thinking, focusing on real-world problems. Second, it moves from Hard System Thinking to Soft System Thinking, emphasizing understanding human experiences. Lastly, it shifts from functionalism to interpretation, using human activity to solve issues. However, Soft System Thinking has shortcomings in extreme subjectivity and conservative system concepts.