Introduction

The national health expenditure (NHE) is growing as a proportion of the United States gross domestic product (GDP). In 2015, NHE represented 17.8% of GDP and is expected to grow to 19.9% by 2025. In 2008, the Institute for Healthcare Improvement (IHI) proposed the Triple Aim, which is a directive to improve population health, improve patient experience of care, and reduce per capita cost of health care. To combat the rise in health care costs, a plethora of strategies and methodologies have been proposed to increase the value and reduce the cost of health care delivery. One of these methodologies is Lean production, which is a method pioneered in the automobile industry by Toyota Motor Corporation. Lean production is founded on two basic tenets: continuous improvement and respect for people, thereby creating an organization that values employee contributions and promotes an environment in which products are created at a higher quality with lower cost. This philosophy is rapidly gaining popularity among hospital systems as part of their approaches to improve the quality of care and reduce the cost of care delivery. Many aspects of health care have been scrutinized and improved using Lean methods, including improving on-time first start cases, decreasing turnover times, and redesigning surgical workflows. Our group is in the process of applying Lean methods to increase the efficiency of the surgical procedure itself.

Lean Production

Lean production has its roots at the Toyota Motor Corporation in Japan in the 1940s. The system was based on the understanding that only a small fraction of the total time and effort to create a product added value to the end customer. By focusing on the value to the end customer, the manufacturing process is optimized.Employees at all levels of the organization are charged with design and production of a product. This allows for all members of the team to improve continuously a process or product. This also emphasizes a “pull” system in which a product is created when it is needed by the customer. This is in contradistinction to the Western philosophy of mass production, which aims to create high volumes of standardized products. With mass production, there is a hierarchical management structure with skilled professionals involved in the design of a process or product and unskilled or semiskilled workers to produce the product. Ultimately, mass production aims for a product that is “good enough,” while Lean production aims for perfection.

In order to create perfection, there are three core principles of Lean: the identification of value, the elimination of waste, and the generation of flow. This process of iterative improvement ultimately creates a perfectly efficient system. The value of a process or step is defined by its direct benefit to the customer. In the ideal case, all steps in a process would add value to the final product. However, some steps do not provide value but are necessary. In the case of automobile production, a seat belt system provides value for the customer, whereas transporting the seat belt to the vehicle and testing the seat belt to ensure proper function does not add value but is necessary. In health care, administering medication is a similar example. In this scenario, the customer (i.e., the patient) receives value when he or she is administered the correct medication. Steps that are necessary but do not add value include procurement of the medication from the supplier, transport of the correct medication to the appropriate unit, and verification of the correct medication and the correct patient. Wastes are categorized into one of seven categories: transport, inventory, motion, waiting, overprocessing, overproduction, and defects. Minimization and reduction of waste leads to increase in the efficiency of the process. So, in the example of medication administration, placing the pharmacy near the patient decreases transport waste, reducing the number of handoffs decreases motion waste, and ensuring the correct dose of medication reduces overproduction waste. The generation of flow, then, is the concept of providing a product or service to the customer when he or she desires it. An example from the automobile industry is a system with perfect flow that produces an automobile only when it is desired by the customer. In this case, there would not be a standing supply of automobiles. Likewise, a surgical implant should be ready to use when a surgeon asks for it and there should not be an excessive inventory.