On the face of it, lean manufacturing, which is used by Toyota and other major global companies, doesn’t seem to fit very well into the world of medicine.

But, on closer examination, surgeons are beginning to see that lean has a good deal in common with the scientific method used in research – it’s just a matter of terminology, although it’s important to point out that this isn’t like randomized controlled trials; instead, it’s about testing hypotheses.

Indeed, the overall goal of lean is to define and refine a process, and then make the end product better for the customer; in medicine, that’s the patient.

At Toyota, it’s all about how they put cars together; in surgery, it’s how we move a patient through the health care system – from referral to the clinic, to the operating and recovery rooms, the hospital bed and discharge, and then back to the clinic for follow up.

Every aspect of patient care is included in lean, including how the pharmacy, central supply, laboratory, and radiology departments, plus a whole host of other services, interact with the patient.

This continuum of care is written out pictorially, in the same way a chemist would write a complex chemical reaction. Using lean terminology, this is called a value stream. The term “value” means what parts of the stream a patient or customer is willing to pay for.

It’s important to realize that perhaps 90 percent of this, or, for that matter, any other process is inefficient or wasted energy that’s not of value to the patient. This includes waiting in the waiting room or nurses searching for supplies. Obviously, these activities don’t add value, and patients certainly don’t want to pay for them.

By writing out a value stream, though, it’s possible to determine what works in the system, and what doesn’t. In this way, we can focus on the 90 percent that needs revision.

Each area of focus is addressed by what we call a rapid process improvement workshop (RPIW). And each RPIW is part of a cycle where data is gathered, a plan is made and carried out, and then the results of the changes are measured.

This cycle is called plan, do, check, and act. In scientific terms, it’s no different from the experimental method doctors learned in medical school, where a hypothesis is made, experiments are performed, data is gathered, and refinements to the process are initiated.

What’s appealing to physicians here is that the methodology is data-driven, in the same way a scientific experiment would be. When various opinions come up, it’s  difficult to argue with data-driven facts, and this helps put people on the same page as they try to refine a process. Of course, that means there are a lot of hours spent gathering the data; this is labor-intensive, but the end results are very worthwhile.

This methodology has been adopted at Seattle Children’s throughout the hospital – in the clinics, the operating room, and on the patient wards.

In the division of Pediatric General and Thoracic Surgery, for example, we have used lean to significantly increase the amount of time our patients spend face to face with health care providers in our clinics. Wait times have decreased, and, as a result, we’ve seen increases in both patient satisfaction and job satisfaction for our clinic staff, nurses, medical assistants and physicians.

We have also used this methodology to improve patient safety.

One particularly striking example here is that we use checklists in the operating room, just like an airline pilot uses in the cockpit of an airplane. This methodology ensures that everything needed for an operation is present and available, and that no details are missed.

Lean originally seemed irrelevant to medicine, and much better suited to the assembly line in an automobile factory; but we’ve seen – and  proven – that it’s very helpful to manufacturers and surgeons alike, and that customers and patients truly benefit in the end.

John Waldhausen, MD is chief of the Division of General and Thoracic Surgery at Seattle Children’s Hospital, and a professor in the Department of Surgery at the University of Washington School of Medicine. He is also the director of the pediatric surgery fellowship program.

In addition to his work in pediatric general and thoracic surgery, he is also an attending for the Division of Transplant Surgery. Additionally, he attends at Seattle Children’s clinics in Federal Way, Bellevue and the TriCities. Waldhausen’s primary research is in clinical outcomes. His clinical activities cover the broad range of pediatric surgery with a focus on minimally invasive surgery, congenital surgical problems and pediatric cancer surgery.


If you’d like to arrange an interview with Dr. Waldhausen, please contact Children’s PR team at 206-987-4500 or press@seattlechildrens.org.