A background on the field of operations management and the Lean management philosophy

The field of operations management is a component of business that concerns itself with structuring operations to effectively meet customer requirements through the most efficient use of resources.1 In general, operations management focuses on increasing the percentage of value-added activities (eg, those activities that directly contribute to the production of a good for which the market demands and will pay) in a particular process, and reducing, or completely eliminating, activities that do not add value. The Toyota Production Systems (TPS), or Lean Manufacturing as it is more generically referred to, is a subset of operations management that combines the efforts aimed at improving operational efficiency with a large emphasis on training and workforce development.

Lean Manufacturing is a term that was first coined in 1988, by John Krafcik, to describe production principles witnessed at the Toyota-GM NUMMI plant in Fremont, California.2 These production principles were derived from iterations of management strategies first conceptualized by turn of the century efficiency leaders such as Frederick Winslow Taylor and Henry Ford. These concepts in turn were transplanted to the Japanese manufacturing industry primarily during the reconstruction period following the conclusion of the Second World War. Although the tools utilized in Lean Manufacturing can be attributed to many firms in the Japanese manufacturing industry, the principle architect transforming these tools into a philosophy is the Toyota Motor Company. Facing both financial and material constraints, and standing on the precipice of bankruptcy, Toyota developed many of these tools and techniques out of necessity, iteratively and over a number of years. Each tool and technique that Toyota developed laid the foundation for the next, and as such each tool has a critical dependence on the other tools in the system.

Both as a management philosophy and as a manufacturing strategy, Lean's primary focus is the creation of value for the customer through the relentless and iterative elimination of both waste (muda) and variation (mura). Working from the perspective of the customer, Lean defines value as any action or process for which the customer would be willing to pay.3 In healthcare the value proposition translates to any action or process that directly contributes to the care of the patient. Essentially, Lean is centered on creating more value for the customer with less work.

A central tenet of the TPS is that those doing the work should be the ones to identify the problems and design the solutions.4 In order to create a workforce capable of identify problems and designing solutions, significant emphasis is placed on establishing process stability through standardization, and leveraging that standardization as the basis not only for training new employees, but also for continuous improvements.5 Numerous companies, across multiple sectors of industry, have applied the concepts and principles of operations management, and Lean management, to their operations with great success.6 Conversely, the hospital industry has in many ways lagged behind other industries with respect to adopting the concepts and principles within the broader field of operations management,7 and Lean specifically. In fact, some hospital administrators, physicians and other clinical leaders have even gone so far as to outrightly reject comparison with other industries that have managed to cut cost much more effectively, arguing that the personal attention required by, and/or variation in caring for, each individual patient preclude them from such comparisons. In other words, because of the variability associated with treating illness and disease, the processes involved in such treatment cannot be as tightly controlled as those germane to manufacturing without an unacceptable impact on the quality of patient care. However, it has been argued that the poor management of the variability in treatment described above contributes to the numerous and often preventable medical errors that occur in hospitals each year; errors that result in approximately 98 000 deaths per annum.8 That is, standardization of care, through Lean, would likely have benefits beyond enhancing operational efficiency in improving patient safety.

Lean in a hospital environment

Typical of organizations that adopt Lean (with hospitals being no exception), the tendency is to implement only one or a few tools from the Lean management system, and apply those tools to only one process step in a sequence of process steps (or value chain as it is referred to in Lean) that contribute to the overall treatment of the patient. What many adopting hospitals fail to recognize, perhaps in their well-intentioned haste to improve their practice, is that the individual Lean tools used to improve a process step, like the individual process step targeted for improvement, are necessary components of a larger system.5 By optimizing only one process step in the entire value chain, you run the risk of suboptimizing upstream and/or downstream components, and therefore the entire value chain. Implementing improvements in isolation such as this would be not unlike the coxswain of an eight-member crew boat asking one crew member to row at a different rate from the other seven members of the boat; naturally the timing, direction and safety of the entire boat would be negatively affected. In other words, by focusing on improving the efficiency of a single process step, one sacrifices the efficiency of the entire system.9 The chances of a successful Lean implementation are greatly improved when a thorough understanding of the entire value chain is developed prior to engaging in any improvement activities.9

Furthermore, adopters of Lean can sometimes ignore the central tenets of the Lean philosophy (ie, developing human infrastructure10 and immediately attempt to leverage Lean concepts like Just-In-Time (ie, an inventory strategy that strives to reduce in-process inventory and therefore its associated costs) or Jidoka (ie, automation of the error detection, typically of a machine, to prevent the production of defective products) without focusing first on the more tedious, but ultimately more necessary, foundational tools like developing standard work and performing 5S (a workplace organization methodology explained in greater detail below). TPS defines foundational tools as those that bring about operational stability, a necessary condition for continuous improvement.11 The benefit from the aforementioned foundational tools should not be discounted in favor of a perceived immediate solution afforded by the higher-level tools. Despite it being tedious and yielding little immediate benefit, the act of performing the foundational activities of Lean first is that it requires staff involvement, ensuring both their buy-in and that all are trained on, and operating in accordance with, a single standard. Solutions achieved from the immediate application of higher-level tools are often not fully recognized or short-lived precisely because the time needed to develop staff to work within a Lean system has not been dedicated.10 It is the establishment of this initial operational stability that makes all future improvements possible.

The MGH neurointerventional experience

With strong leadership support, that is, the chairman and executive director of the Department of Radiology, and, knowing these and other common pitfalls associated with undertaking a Lean engagement,12 the NI service at the MGH engaged in the following deliberate and measured approach to converting its operations to run Lean. While beyond the scope of this article to be completely inclusive of all elements of the transition to Lean, in the remaining text we will focus on the key features of our approach.

Specifically identify the value chain to be improved

We identified the specific value chain to target for Lean conversion. The first step in identifying the value chain targeted for Lean conversion is to identify the specific product families that are being targeted for improvement. A product family is any group of goods or services that move through similar downstream process steps and utilize similar equipment and resources.9 The product families selected by the NI leadership were diagnostic angiographies and embolizations performed under either conscious sedation or anesthesia for both inpatients and outpatients. For these product families the value chain targeted for Lean conversion began at the point of ordering the procedure and concluded with the completion of the final radiologic report.

Once the product families and value chain are identified, a charter is drafted for the engagement. The charter occupies a single 11×17 inch piece of paper, known and referred to in Lean as an A3, and identifies the following details: the individuals involved in the engagement, their roles and responsibilities to the engagement for each individual, the problem or case for change, the goals and the time frame for the engagement. This charter document is then communicated broadly to all staff in NI and in the Department.

Educate staff in the operational areas targeted for improvement

Staff across multiple role groups including physicians, nurse practitioners, staff nurses, technologists and administrators, in NI participated in a 6-h educational session on the concepts and principles of the Lean Manufacturing System. To accommodate this 6-h commitment, no non-emergent elective procedures were scheduled for the identified date. The participants were provided didactic education on the history of the Toyota Motor Company, and the iterative manner in which the TPS was developed, as well as some of the common Lean tools used to improve processes. This didactic education was paired with a simulation exercise in which the participants were asked to construct Lego robots over five 5-min rounds. Over the course of the five rounds of the simulation exercise the method of production was transformed from a traditional batch and queue manufacturing system (ie, a system in which work-in-process inventory is pushed to downstream process steps with little to no regard for the rate of customer demand, resulting in build-up of in-process inventory between process steps) to a Lean flow and pull manufacturing system (ie, a system in which downstream process steps signal upstream process steps to produce only when a customer order is received, as such, only what is needed by the customer is produced and there is little to no in-process inventory) . Following the first round of the simulation and prior to each subsequent round, the participants were educated on a specific Lean tool and asked to apply that tool to the production process. In the final round of the simulation the participants were allowed to utilize any and all Lean tools, for which they received education, and design their own method of production.

Understand the entire value chain to be improved

Representatives from each role group of the NI staff participated in a 3-day value stream mapping (VSM) workshop. To accommodate the 3-day commitment, no non-emergent elective procedures were scheduled for the identified date. At the end of each day the VSM participants reported their progress to the Executive Director for the Department and the Chief of the Department. On the first day of the VSM workshop the participants observed, identified and documented each process step of the current state of operations from scheduling the exam to completion of the final report by the proceduralist. On the second day the participants identified a future state for the operations. The future state needed to be achievable in 6–18 months.

Identify the improvements to be made and the sequence in which they should be made according to necessity and/or institutional/regulatory priority

On the third and final day of the VSM workshop the participants identified the improvements required to achieve the identified future state, the sequence in which these improvements would be made, and assigned deadlines by, and resources with, which the improvements would be made.

Establish initial operational stability: 5S and standard work

Of the identified solutions those that were prioritized first were those that focused on developing human infrastructure and establishing operational stability of the NI clinical and business practices. To that end the team began first with implementing the workplace organization methodology known as 5S (Sorting, Straightening, Shining, Standardizing and Sustaining). This method of workplace organization establishes a clear understanding among all employees of both where all materials will be stored and how this new standard will be maintained. The key distinction between 5S and other workplace organization methodologies is that 5S requires that the employees working in the operational area being organized determine where the items will be stored to facilitate the most effective and efficient workflow.13 As with all Lean engagements, the implementation of 5S requires that management dedicate time for employees to participate in the process without having to balance normal day-to-day job tasks. Because the areas targeted for workplace organization are occupied by patient care activities during normal business hours, the 5S activities needed to occur on the weekends. Employees were offered overtime to come in on three separate Saturdays for 8 h each Saturday, during which the 5S activities would be performed. After having participated in both the 6-h educational session and 3-day VSM workshop, and combined with the prospect of receiving compensation for their participation, we enjoyed excellent participation.

The establishment of standard work for each role group and for each process was the next step in establishing operational stability. Standard work can be thought of as the best combination of activities that will limit activities that don't add value. Pursuant to that goal is the provision of the highest quality healthcare. For each process (eg, ordering the procedure, scheduling of the patient, nursing pre-procedure work-up, in-room patient preparation, etc) a 4-h block of time was dedicated to identifying the individual steps within that process. The product of these 4-h workshops was a work instruction sheet (WIS) for each process and specific to each role group. In other words, there is now a WIS for the Technologist's responsibilities during in-room patient preparation and there is a WIS for the nurse's responsibilities during in-room patient preparation. Because only a subset of staff participated in the creation of these WISs, the WISs were circulated to the remainder of the staff for comments and revisions prior to implementation. Furthermore, because today's standardization is only the foundation for tomorrow's improvement,14 time is dedicated to revisit and revise the WIS each week.

Implement solutions, leveraging the appropriate Lean tools

We have identified over 100 improvements to transform the current state operation into the identified future state. Many of the identified improvements will leverage Lean tools. For example we will leverage recently purchased radio frequency identification (RFID) technology to automate both the purchase and billing of products used to treat patients. This technological solution is supported by workflow changes embedded in the identified standard work (reflected in the appropriate WIS) and will enable just-in-time management of materials needed to treat the patient. Additionally, we will leverage heijunka boards, which are visual representations of the daily [patient] schedule, in each operational area to ensure that we are performing each process within our identified task time, or the rate of customer demand as determined by the available time per shift divided by the demand for that shift.

Dedicate time to iterate on each improvement

The process stability established in the proceeding steps and the improvements implemented as a result of this Lean engagement should not remain stagnant after they are initially achieved. As such, dedicated time to revisit and revise each standard established and each improvement made is identified up front and in the charter document. Each day during the business week, a 15 min stand-up meeting is conducted at 7:30 a.m. in the hallway immediately outside of the NI Radiology procedure rooms. All available members of the team attend. The purpose of the meeting is to discuss progress of any implemented solutions or standards, identify remediation activities and responsibilities if necessary, and discuss daily and/or upcoming improvements. In addition, weekly 30-min meetings with the NI Radiology staff are held to discuss and revise, if necessary, the WIS for each process. To monitor compliance with standards and implemented improvements, audit sheets are created and posted in each operational area. Audit responsibilities are assigned not only to leadership, but also to frontline staff and are rotated each month. It is important to note that these audits are not punitive, but are used to inform the team of any revisions that may need to be made to the established standards or implemented improvements. As such employee involvement in the audit process is critical.