In my last posting I
presented the framework for a consulting engagement in the healthcare
field. I finished that posting by saying
that several of the new Green Belt graduates had taken what they had learned
from the training and applied it to their own work environment. In today’s posting I want to explain what
these students had done with their training as well as part of their outcomes. One thing I told the students during their “graduation
ceremony” was to take their new tools and make them their own. My concern has always been that when people
learn a new tool or technique that they believe it can only be used as
intended. This is far from the truth
because if this were the case, then new ways to use these tools and techniques
would never be discovered and shared.
This posting is rather lengthy, but I felt compelled to provide our new
readers some background information on one of the improvement tools…..the
Interference Diagram.
Two of the Green Belt students
had been working with a team on a flow issue within the facility and had really
gotten nowhere in several months. After
they finished their training the team had a regularly scheduled meeting and the
two students worked with the team leader to create a current state process map
of a requisition to payment process.
This was an important step because for the first time ever the entire
team could now visualize the entire process from beginning to end. They spent quite a bit of time reviewing what
they had constructed and then categorized each step as either value-added
(green dots), non-value added (red dots) or non-value added but necessary
(yellow dots). Based upon the results of
this value analysis, the team identified the system constraint and then used
their training to construct a future state process map. Upon completion of the
future state map the team immediately realized that they could remove five
steps in the process. These five steps
required a significant amount of time to complete, so by simply mapping the
process and identifying and exploiting the constraint, the team reached their cycle
time reduction goal!
Last week I went back to
this facility and delivered some additional training on a couple of other
important tools……the Intermediate Objectives Map and the Interference
Diagram. I’ve written about both of
these tools before on this blog, so you can review both of them if you’re new
to my blog. Two postings, Focus and
Leverage Part 51 summarizes the IO Map while Focus and Leverage Part 57
discusses the Interference Diagram, although there are other postings for each
one in this blog. It is this last tool,
the Interference Diagram that two of the new Green Belt students used to solve
their problem. But before I discuss what
they did, let me summarize some key points in using the Interference Diagram
for those new to this blog.
For
those of us engaged in performance improvement initiatives there seems to be a
constant bombardment of “things” that seem get in the way of what we’re trying
to accomplish. Things that interfere with our attempts
to achieve a goal or objective in our quest to make things better. Some of
these things come out of nowhere in the name of uncertainty to stifle our
efforts and still others are there just waiting to be found and acted upon.
Wouldn’t it be great if there was a way, or at least a tool, to help visualize
these “things” so that we could do something about them? Life would be so much
easier wouldn’t it? Good news….such a tool does exist for identifying the
myriad of business, production, healthcare and manufacturing issues that face
us every day. It’s called an Interference Diagram (ID).
Most
of you have probably never have seen or even heard of an ID before. Its origins
date back to the mid-1990’s with Bob Fox and the TOC Center in New Haven,
Connecticut. As a thinking tool it has not been well publicized and as such, is
not well known. But just because it hasn’t been well publicized, don’t
underestimate its importance from a problem solving perspective. The endearing
qualities of the ID is that it’s both simple to learn and construct and is
quite robust in its application. The ID is a thinking tool that offers the
capacity to define and visualize those interferences or obstacles that block or
hinder your ability to achieve a specific goal or outcome. It’s always far
easier to define what we want, but much more difficult to define why we can’t
have it and the ID helps us do that. I
use it often to exploit the system constraint after mapping the process to
identify it.
The ID can be used at many different
organizational levels to understand why things at all levels don’t happen or
work the way we want them to. The ID can be used as a stand-alone tool or it
can be used in conjunction with other tools, so its uses are multiple. As a
stand-alone tool it provides a discrete analysis to better define and
understand the obstacles that prevent accomplishment of our goal. But in a
broader application it can be used to supplement the other, more common systems
thinking tools developed by Dr. Goldratt as well as his Five Focusing Steps. No
matter which way it is used, the end results can be very dynamic.
The Interference Diagram is quite simple to
construct as depicted in Figure 1. The first step in its construction is to
decide what it is you want more of or what your goal or objective is. When
you’ve decided what that is, write it inside the circle in the center of a
white board or piece of paper. Make sure that whatever you write here is a
succinct, precise statement so that it’s easy to work with.
After you’ve considered and recorded what it is
you want more of, think to yourself “What prevents me from getting more of what
I want?” The answer to this simple question becomes the interferences that you
record in the boxes surrounding your goal. Continue to list your interferences
until you are satisfied that your list is complete enough to move on. There are
really no rules that govern a specific number of interferences you can list,
just be sure to list the major
interferences as to why you can’t
achieve what it is that you want more of. Make sure you include things that you
might think you can’t do anything about like lunches and breaks.
Figure 1
If your ID analysis is such where time is an
important factor, then it is important to quantify your interferences as a
function of time. In other words, how much time does this particular
interference take away from what you want? If time is a factor, and most of the
time it will be, then it’s important to keep the time element constant. That
is, record the time element for each individual interference using the same
measure, such as minutes or hours or whatever measure you select per day or
week. As you will see shortly, this will help you prioritize your interferences
in terms of importance and actions. Let’s look at an example.
In
this example, suppose you are working in an Aviation Maintenance, Repair and Overhaul
(MRO) facility and you are responsible for increasing the number of aircraft
available on a daily basis. You haven’t been meeting your contractual targets,
so you’ve been receiving large $ penalty losses. Let’s assume you have already
completed a process analysis using a process map or value stream map and have
determined the location of your system constraint to be the wait time required
to get necessary approvals to permit your maintenance work to begin on the
aircraft. In this scenario you assemble a team of subject matter experts, the
people maintaining, repairing and overhauling the aircraft, and you begin
construction of an ID. Since your constraint has been identified as the wait
time to begin work on the aircraft (or More Wrench Time), you decide that your goal
should be, “Reduced wait time to begin repairs.” You ask the team the following
question, “What is preventing you from beginning work on the aircraft sooner?”
One-by-one you then record both the interference the team members have
described as well as an “estimate” or “guesstimate” of how much time is being
lost for each one.
Figure
2 is an example of the responses (i.e. interferences and estimated times) you
received from the team members and the populated boxes surrounding your goal.
If you just eyeball the interferences, you can see that Incorrect Assignments
is the largest impediment to reducing the wait time to begin repairs at 210
minutes per week. This is followed by paperwork and waiting for the rinse crew
at 120 minutes each. Once you feel confident that you have captured the
predominant interferences, I recommend that you create either a Pareto Chart or
a Pie Chart to prioritize the interferences.
Figure
3 is the Pie Chart of repair time minutes lost per week as a result of the
interferences identified by the team of SME’s. The Pie Chart reflects the
priority order to “attack” these interferences to authorize repairs to begin
sooner on the aircraft. The most
important thing to realize is that of the total available time to work, because
of the Interferences identified, only 42 % of the time the SME’s are actually
working on the aircraft! So by
eliminating, or significantly reducing, the times associated with these
interferences, there will be an immediate gain in the throughput of the process
you are trying to improve and most of the time very little, if any, money is
required to achieve this improvement!
Because
of the length of this posting, in my next posting I’ll get back to our two
other Green Belt students and how they used the Interference Diagram to help
them solve their months-long problem.
Bob
Sproull.
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