655: BCG Managing Director and Partner, Kristy Ellmer, on Why Change Fails and How Great Leaders Build Real Transformation

Description

Kristy Ellmer has spent her career leading large-scale transformations across industries, countries, and operating environments. In this conversation, she explains why most change efforts fail — not because of bad strategy, but because organizations underestimate the human side of execution. A central idea from the discussion is the imbalance between the "what" and the "how" of transformation. Leaders spend enormous energy defining strategy, targets, and operating levers, but far less time on the behaviors and systems required for adoption. As Ellmer explains, "transformations or change are failing… on the elements of the how. It's not because there was bad strategy." She argues that many executives rush from alignment into execution before the organization is ready. One of the most counterintuitive lessons from her work is the need to pause after agreement is reached: "You need to take… up to two months to get organized." Without the right operating structure, early momentum eventually stalls. The conversation also explores why momentum must be designed intentionally. Discussing transformation work at Aetna, Ellmer explains the importance of visible early wins and helping employees understand "what's in it for you." She emphasizes that leaders are "responsible for momentum," not just strategy. Another major theme is resistance to change. Early in her career, Ellmer believed that "everybody will just get on board because things are right." Experience taught her otherwise. Different groups respond to different incentives, fears, and motivations. Her advice: "Be curious" about why people resist rather than assuming they are unwilling to change. She also challenges traditional views of change management, arguing that communication plans and training sessions alone are insufficient. "There is real science now out there on how humans really change," she says, and organizations that ignore that science struggle to achieve lasting adoption. The discussion also covers: why long transformations create fatigue when organiz