In
my last posting I introduced you to some of the more important elements of the
Affordable Care Act including how hospitals might be penalized for readmitting
patients before 30 days have passed and how Medicare reimbursements might be
reduced based upon patient satisfaction scores.
In this posting I want to start a discussion on how hospitals might use
TOC, Lean and Six Sigma to improve the flow of patients through places like the
emergency room and surgery which could have a very positive effect on patient
satisfaction, especially as it relates to patient wait times.
I’ve
talked many times about the concept of the system constraint and why it’s so
important to identify it so that it can be the focus of your improvement
efforts. For those of you new to my blog
I want to back-track a bit and give you the basics of just what a physical
constraint looks like. For those of you
already familiar with these concepts, please be patient. Figure 1 is a cross-section of a very simple
piping diagram with varying diameter pipes with water flowing through this
system via gravity.
Figure
1
Water
enters this system through Section A and continues flowing through Section B
and so forth all the way through the system to the vessel below where the water
collects. The question I always ask is
this. If the rate at which water flows
through this system is not sufficient to meet your needs (i.e. you want more),
what would you have to do to increase the rate of flow of water through this
system. The answer is, of course, that
you would have to increase the diameter of Section E. The next question I always ask is, what would
determine how large to make the new diameter of Section E? The obvious answer is that it would depend
upon how much more water you would need to flow through the system. My next question concerns the other
diameters. Would increasing the diameter
of any other Section increase the flow of water through this system? The answer is no, because Section E controls
the flow of water. In other words,
Section E is the system constraint. So now let’s say that you opened up Section E’s
diameter to what you see in Figure 2.
Figure
2
Once
we opened up the diameter of Section E, more water exited the system, but look
what’s happened to our piping system.
Section B is now controlling the flow of water. In other words, the constraint has moved from
Section E to Section B. So if we wanted even
more water to flow through this system, we would have to focus our efforts on
the new system constraint, Section B.
What we have just experienced is the Theory of Constraint’s process of
on-going improvement (POOGI). Dr. Eli
Goldratt developed this methodology back in the mid 1980’s and wrote about it
in his block buster book, The Goal. In this book he introduces his now famous
Five Focusing Steps:
Step 1: Identify the system constraint.
Step 2: Decide how to exploit the system constraint.
Step 3: Subordinate everything else to the above decision.
Step 4: If necessary, elevate the system constraint.
Step 5: Return to Step 1, but don’t let inertia cause a new
constraint.
In our piping diagram we have completed Steps 1 and 2, identify and decide how to exploit the system constraint. We exploited it by increasing its diameter. Step 3, subordinate,
happened automatically since water was forced to flow at the same rate as the
system constraint. Step 4 merely means
that if the simple things we do to improve or exploit the system constraint
does not result in enough system throughput, then we might have to spend some
money to break the system constraint. Elevating
the constraint simply means that we are increasing the capacity of the
constraint to at least match the demand placed on it. In Step 5, when the constraint moves, we
simply move our improvement effort to it, but we need to review the changes
(e.g. policies, procedures, etc.) to make sure it does not have a negative
effect on the system. That’s what
Goldratt meant by not letting inertia cause a new constraint
So in this simple 5-Step process of on-going improvement we
have increased the capacity of our system.
This same process can be used effectively to improve the throughput of
widgets in a manufacturing process or even people in a healthcare
environment. As I’ve said many times
here, this approach is much more effective than attempting to “solve world
hunger” by attempting to reduce waste and variation everywhere within the
process or system. Just like the large
diameters in our piping system, widening their diameters would have zero impact
on the throughput of water, so to it applies to any system where system
throughput improvement is the objective.
One last point I’d like to make before closing this
posting. It is extremely important to
determine whether a constraint is internal or external to your
organization. An external constraint
occurs when the demand for your products or services is less than your capacity
to supply them. In other words, you
could take on more orders, or in the case of healthcare, more patients than you
currently have without incurring any additional expenses. An internal constraint is exactly the
opposite in that the demand for your products or services exceeds your capacity
to deliver. In healthcare this would
mean that you are unable to process and satisfy the number of patients desiring
your healthcare service. Knowing whether
your constraint is external or internal is important because the actions you
take to relieve the constraint are completely different for each type of
constraint.
In my next several postings we’ll expand upon the concept of
the system constraint and demonstrate how TOC might be used to improve patient
flow in a healthcare setting. We’ll take
a look at how POOGI might be used to improve the flow and synchronization in processes
like a hospital emergency room, a surgical unit, or maybe even a hospital clinic
that treats outpatients. Stay tuned.
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