Wednesday, November 25, 2020

Healthcare Case Study Part 1


 In this series of blog posts, we’re going discuss a case study from the healthcare field. We will discuss a Process Value Stream Analysis (PVSA) project at a hospital located in the Mid-Western part of the United States. The focus of this PVSA was on this facility’s Emergency and Cardiology Departments, where they wanted to improve one of their key performance metrics, Door to Balloon (D2B) Time. For those of you (like me before I started this engagement) who don’t have a clue as to what D2B Time is, let me fill you in. Door to Balloon Time is a time measurement in Emergency Cardiac Care (ECC), specifically in the treatment of ST Segment Elevation Myocardial Infarction (or simply, a STEMI heart attack).


The interval starts with the patient’s arrival in the Emergency Department and ends when a catheter guide wire crosses the culprit lesion in the Cardiac Cath lab. In everyday language, this just means that a balloon is inflated inside one of the heart’s primary blood vessels to allow unimpeded blood flow through the heart. The clock starts ticking either as a walk-in to the Emergency Department or in the field where a patient is being attended to by medical personnel. This metric is enormously important to patients simply because the longer this procedure is delayed, the more damage occurs to the heart muscle due to a lack of oxygen to the heart muscle. It’s damaged because the cause of this problem is typically due to a blockage within the heart that prevents oxygen from being supplied to the heart, and without proper amounts of oxygen, muscle damage results. The inflated balloon “unclogs” the blood vessel. Graphically, door to balloon might look like Figure 1.

Figure 1

I started this event with a training session for the team members focusing on how to use an integrated Theory of Constraints, Lean Six Sigma improvement methodology. I have seen a lot of Process Value Stream Analyses (PVSAs) where waste is identified throughout the process, and then the team works to either reduce it or eliminate all of it. It has been my experience that when attempting to reduce the time it takes to process something through a process, such as this one, by attacking the entire process for waste reduction, teams frequently miss the opportunity to reduce the cycle time much more quickly than they otherwise could have. This is where the Theory of Constraints (TOC) and its Five Focusing Steps offers a much quicker solution to this type of project. Just to review, TOC’s Five Focusing Steps, first introduced by the late Dr. Eli Goldratt.  These five steps are:

  •       Identify the system constraint—In a physical process with numerous processing steps, the constraint is the step with the smallest amount of capacity. Or another way of stating this is the step with the longest processing time.


  •           Decide how to exploit the system constraint—Once the constraint has been identified, this step instructs you to focus your efforts on it and use improvement tools of Lean and Six Sigma to reduce waste and variation, but focus your efforts mostly on the constraint. This does not mean that you can ignore non-constraints, but your primary focus should be on the constraint.


  •       Subordinate everything else to the constraint—In layman’s terms this simply means don’t over-produce on non-constraints, and never let the constraint be starved. In a process like the Door to Balloon time, it would make no sense to push patients into this process, since they would be forced to wait excessively. But of course, the hospital cannot predict when patients with heart attacks will show up needing medical attention. But by constantly trying to reduce the constraint’s time, the wait time should be continuously reduced.


  •            If necessary, elevate the constraint—This simply means that if you have done everything you can to increase the capacity of the constraint in Step 2, and it’s still not enough to satisfy the demand placed on it, then you might have to spend money by hiring additional people, purchasing additional equipment, etc. That is, anything that would reduce the time in the constraint.


  •           Return to Step 1, but don’t let inertia create a new constraint—Once the constraint’s required capacity has been achieved, the system constraint could move to a new location within the process. When this happens, it is necessary to move your improvement efforts to the new constraint if further improvement is needed. What is thing about inertia? What Goldratt meant by that was to make sure things you have put in place to break the original constraint (e.g. procedures, policies, etc.) are not limiting the throughput of the process. If necessary, you may need to remove them.


In my next post, I will continue with this case study.