TOC in The Emergency Room


Belle Chasse, LA, October 25, 2005 – This is the main patient area inside of the Mobile Medical Unit being operated in Belle Chasse, Louisiana. This configuration is an emergency department with minor surgery capability. Robert Kaufmann/FEMA
ISE Magazine Volume : 50 Number: 7
By Vinny Monteiro

Applying lean to your glaring constraints makes things better for doctors, patients and support personnel

To improve any process, the most effective method is to follow a structured set of steps to identify and remove the limiting factors inherent to the system. This approach works remarkably well, as illustrated by the recent success of improving emergency department operations at a hospital in Texas. This hospital’s operational excellence team used a framework known as the theory of constraints (TOC) as well as lean techniques to find and address the problems in the system, experiencing a high level of success in nearly every area in less than 90 days.


Long length of stay (LOS) in the emergency department has several negative outcomes for the patients as well as the hospital. Patient and physician satisfaction decreases, and the hospital’s ability to see all patients in a timely manner is compromised. Wait times increase, revenue for the hospital decreases as fewer patients are being seen, and some patients will arrive in the waiting room and decide to leave and go to another medical center, measured as patients who left without being seen (LWBS).

Another concern includes the need to make sure no patient leaves the emergency department without being registered. Besides the fact that revenue may be lost due to the inability to bill the insurance company or patient, a major concern is the legal risk to the hospital, not to mention the bad public relations, if patients leave in an unstable condition and later suffer bad outcomes because they were not cared for in a timely fashion.


At the start of the project, it was vital to use the theory of constraints framework. When doing process improvement initiatives, TOC gives the proper focus and shows where efforts need to be concentrated, whereas lean tools allow the team to remove waste and improve the areas that need to be improved.

TOC helps a project leader understand the three basic questions: What to change? What to change to? How to cause the change?

Knowing the answer to these three questions allows for a thorough understanding of the situation, the cause of the issue and where changes need to happen to eliminate the negative effects. One would expect a manager to be able to easily figure these things out, and yet they are often the hardest questions to answer. Knowing the problem (what to change), the solution (what to change to), and the steps for implementation (how to cause the change) are necessary to successfully improving any process.

The explicit goal was to improve disposition-to-discharge time, patient wait times, communication between all stakeholders in discharging a patient, and ultimately throughput and revenue in the emergency department.

So, the questions were: What to change? Where do we need to focus to achieve the desired results? Will the changes be enough to have an impact? Next, it is important to know: What to change to? It was clear that discharge times were longer than desired, so the problem was evident, and the goal was set to be under 20 minutes.

However, what wasn’t as obvious was what the process needed to become. Of all the things that could be improved, where was the best place to start?

Identify the constraint

The TOC framework consists of five focusing steps that help structure the approach. The first step is to “Identify the system’s constraint,” or the “bottleneck.” This may or may not be easy to find (given that hospitals are extremely complex systems), but if it can be found, it gives great leverage. If the bottleneck is not the focus of all efforts, any improvements made in any other area will not give the increased throughput desired.

The kickoff meeting consisted entirely of subject-matter experts and stakeholders for this patient journey. It included the director, nurses, techs, an emergency department physician and a cleaning person (EVS), to name a few. It started with just-in-time training to make sure everyone understood process mapping, standard work, visual management and the types of wastes. Then everyone went through an exercise to show how bottlenecks limit the throughput of the system and how improving the constraint is the best way to produce results.

Once the process map was created, it was then easier to demonstrate that the time the patient stays in the room was actually the bottleneck, and reducing the time a patient stays in the room was the only way to improve throughput. To this end, the team then categorized which steps performed while inside the room add value, which are wasteful, and which can be done outside the room. As evidenced by the steps taken, any activity that can be shortened, eliminated or moved elsewhere would help in improving flow.

Since the leadership team chose to improve dispo-to-discharge, this was the particular area in which the improvement team could shorten a patient’s time spent in the room. From the moment the physician decided a patient was ready to be discharged, any minute beyond that time was considered a waste for the patient who remained in the room. At this point, a decision had been made, the team knew what needed to be done and anything improved there would improve the system as a whole.

Others recognizing the importance of health systems engineering

For the sake of the problem statement, let’s establish some terms: “Value-added room time” is the time when the patient is actually receiving treatment in the room and actions are being taken to advance the patient from the current state to the desired state (being treated and either discharged or admitted to the hospital). “Wasted room time” is considered any time the patient is in the room but doesn’t need to be there (or isn’t being treated) or any time there is no patient in the room (aka “dead bed time”).

There are two possible areas to tackle here. One is to minimize both the time the patient is in the room waiting to be discharged, and next is the time it takes to turn an empty room around so a new patient can be treated. Coordination of efforts from several stakeholders is necessary to make sure this happens. The first step, “Identify the system constraint,” has been completed. It was clear that the ability to see more patients in the emergency department is limited by the time patients stay in the room. A snapshot of the utilization of an emergency department room, the constraint, would look something like

Exploit the system’s constraint

Another way of saying “exploiting the constraint” is “make the best use of your constraint.” There was group consensus that the “value-added room time” was the most precious commodity in the whole emergency department, and that making the most use of the room time was the only way to see more patients quicker. The improvement team had to find ways to remove the barriers listed above to create enough capacity to see all the patients coming through the door in a timely manner.

One key is to subordinate everything else to the above decision.

Next, it was decided that the best way to make sure this happens (at least initially, to work through the barriers) was to create a “resource team” to be responsible for discharges. This team, consisting of a nurse and a tech, had the goal of tackling the two areas identified for improvement, which were the time patients were in the room after they were cleared by the physician and the time the room stayed empty between a patient leaving and a new patient being brought to the room (dead bed time). This resource team would first make sure any patient ready to be discharged was discharged promptly, and second, the team would bring a new patient into the room as soon as it was ready.

This resource team solved nearly all the issues brought up by using lean tools to eliminate waste in the system. Creating a trigger for the team to know when a patient has received discharge orders ensured that the team was making the best use of time. Team members made a point of keeping an eye on the time the patient spent at each step in the journey, and if the patient spent too long anywhere in the process without making progress, there would be an intervention to help the patients move forward. Not all waste factors could be eliminated (such as a patient waiting on a ride), but they could be minimized, and the actual factors in this category were few.

Some might see this solution and protest: “But isn’t it a waste of valuable resources? Shouldn’t we have nurses and techs see patients? That’s what they’re here for.” But by further analyzing workflow data and even running simulations of different scenarios, it was found that, in this specific environment, it was preferable to allocate certain resources to help in these tasks in order to see improvement for the whole department.


The end of the 90-day project came with the following successes:

  • Dispo-to-discharge time at 19 minutes (almost half of baseline time)
  • Increased patient and physician satisfaction
  • Average number of patients in the waiting room declined from 11 to 6.
  • Average time waiting for patients in the waiting room (at peak times) declined from 20 minutes to 8 minutes.
  • 12 percent reduction in length of stay (LOS)
  • Left without being seen (LWBS) declined from 2.75 percent to 1.3 percent (and improving).
  • Net annual financial value-added impact of $480,000 through revenue enhancement

Focus first; then fix

By using TOC tools to understand where to focus and how to keep the big picture in mind and then applying lean tools to eliminate waste and improve the constraint, the improvement team was able make a positive impact in emergency department operations.

Patients could be seen faster and go home quicker. Physician satisfaction increased as things ran more smoothly. Because they were no longer being pulled in so many directions, nurses appreciated the changes. Plus they felt they had the help they needed to best treat their patients.

And, of course, management was pleased to see patient satisfaction scores go up and revenue increase.

After the 90-day project was completed, staffers continued to take steps to further improve the process. As they continue to embed in the culture of the emergency department team the importance of constantly exploiting the constraint, they are also working on better ways to notify staff when a patient is ready to be discharged. Because of these initiatives, the time windows in which the “resource team” is being used have decreased to only peak times, thus freeing up staff for other patient-centered tasks.

The efforts to reduce wasted time in the emergency department were a success thanks to a focused and systematic approach to problem identification, as well as a fervent commitment from members from every department involved. The TOC and lean frameworks can be applied to find improvements to any system, as long as they are implemented conscientiously and consistently with a motivated team and a clear vision behind them.