In most cases the largest cause
in a Pareto chart is the first target for improving a process. However, in this
example the students aren’t complaining about the time they spend in the
stacks. The students’ primary complaint is about the second shortest step in
the overall process. Based on these observations the process improvement team
decides to divide the problem into two pieces. First they will determine if
they can reduce the amount of data required for the checkout process, thereby
addressing the main complain of the students, and second they will analyze the
process in more detail to see if the overall time can be shortened without
major investments in new equipment or facilities.
Examining the rational for requiring
the student’s local and home addresses for checking out books determined that
this policy traces to the era before the college established computer databases
of student information and the use of student ID numbers. It was incorporated
into the checkout software just because it was part of the process at the time
the software was introduced. Therefore the team checked to ensure they could
get access to a student’s addresses if they had a student’s name and ID number.
Confirming that they could they dropped this requirement from the checkout
process and modified the library’s policy documentation to reflect this change.
All librarians and assistant librarians were notified that student address data
is no longer to be collected.
The team examined the raw data
collected on the individuals using the library to see if any additional insight
might be gained on the process. This led to discussions with the assistant
librarian that collected the data. The
discussions revealed that if a student returned to the catalog after being in
the stacks then each of the times the student spent waiting for the catalog
computer, using the computer or searching the stacks were added together. For
example, if a student returned to the catalog computer three times then the total
time using the catalog computer is the sum of the three independent times.
Examining the raw data indicates that about 50% of the students return to the
catalog more than once and about 25% return three or more times. Discussions
with students returning to the catalog computer more than once showed that
these students were noting only one book at a time when doing a catalog search.
They then go to the stacks, examine the book and if it doesn’t have the
information they need they return to the catalog computer, repeat the search
and examine the next most likely book.
Based on this new information
the team concluded that the instructions for using the catalog are inadequate,
possibly explaining why 81% of those surveyed found the instructions of little
or no use. The team modified the instructions to include recommending that the
students note several books from each search that might contain what they need
before going to the stacks and examining any of the books. The modified
instructions were posted beside the catalog computers and notices were posted
reminding the library users that the instructions had changed.
Next the team prepared a work
flow diagram and a deployment chart to see if any additional insight into
improving the process is provided by either of these tools. Work flow diagrams
and deployment charts are items that I have found useful that are not in my
1987 copy of the Memory Jogger. These are based on process flow charts and add
information not usually associated with flow charts that helps identify process
improvements. For our purposes the definitions of these items are:
•
Flowchart- A schematic step by step description of a
process. It can be top level or very detailed.
•
Work flow diagram- A floor plan of the workspace that
includes the movements of people and items involved with the process.
•
Deployment Chart- A matrix of process steps and workers
showing who is responsible for each step.
Simple
examples better explain why these diagrams and charts are useful. Important
information for process improvement efforts not included on flow charts is the
spatial relationships of steps in the process and who the primary and secondary
workers are that are responsible for each step.
This information is provided in work flow diagrams and deployment charts.
Examples of these are shown in figures 26 and 27 for the book checkout process.
Figure 26 Work flow diagram for checking out a
book.
The work flow
in figure 26 shows that this work space can be improved to make the student’s
job easier by moving the card catalog closer to the stacks so that students
that have to make a second and third trip to card catalog need to take fewer
steps. The work space can be improved to make the librarian’s job easier by
moving the librarian’s computer closer to where the students bring their books
at the checkout station so the librarian doesn’t have to move back and forth to
access the computer and work with the student. These improvements are not
apparent from just the process flow chart illustrated in figure 21.
Figure 27 Deployment chart for
finding and checking out a book. (The rectangles indicate a primary
responsibility and the ovals a secondary responsibility for a given task)
The
deployment chart shown in figure 27 adds new information to the process
description, although in this simple case it doesn’t suggest any improvements
to the process. An alternate version of the deployment chart lists process
steps under columns labeled with the titles of individual workers involved in
the process. In general it is good practice for process improvement teams to
start by developing the process flow chart, the work flow diagram and the
deployment chart as a first step and to try various forms of these charts and
diagrams rather than just preparing a single flow chart before beginning
analysis.
Often just
putting charts and diagrams on paper suggests simple improvements, as the work
flow diagram did for the book check out process. The observant student will
have noticed that the description of the library processes is much simpler than
what actually happens. For example, the flow chart, work flow diagram and
deployment charts lack the loop back to the catalog if the student doesn’t find
the information needed in the books examined from the first search of the
catalog. If all three charts are developed at the beginning of a process
improvement activity it is more likely that missing steps are identified.
Checking the effectiveness of candidate
improvements
The process improvement team
moved the catalog computer and the checkout computer as suggested by the work
flow diagram. They then collected new data for a week to see if these changes
and the changes they had made to the checkout process had any impact on the
number of complaints received or on the time to find and check out books. The
post improvement data is shown in figures 28 and 29.
Figure 28 Post
improvement complaint check sheet.
Figure 29 Post
improvement times for finding and checking out books.
The post
improvement data shown in figures 28 and 29 indicate that the objective of
reducing the number of complaints was met and some reduction in the average
time to find and checkout books was achieved. Although only a small reduction
in time the students spend in the stacks was achieved there is a significant
reduction in all other times. The students spend less time in queues and less
time providing data to the librarians. Note that the time the librarians spend
in processing books is also cut in half. This is attributed to the reduction in
time listening to students complaining. The time listening to complaints was
also increasing the time students had to wait in the queue for checking out
books. The librarians found that they had more time for other work and they
were enjoying their jobs more without having to listen to so many complaints.
This example of
process improvement contains several lessons learned that are worth listing.
These include:
·
Processes are often much more complex in
actuality than workers first perceive. This is usually because they think of
how the process ought to work rather than how it actually does.
·
First attempts at collecting data often miss key
data because of incomplete descriptions of processes.
·
Fixing a problem in one step can often have
unexpected benefits in other steps in a process. In the library example
eliminating the need for providing unnecessary data to the librarians not only
reduced complaints it reduced the times librarians spent in listening to the
complaints and the time students spent in queues waiting for free librarians.
·
Processes often contain unnecessary steps due to
some past rational that no longer applies.
·
Improving processes almost always makes workers
jobs easier and if continued over time can reduce the number of workers
required to carry out processes.
Process improvement
should be an ongoing effort and if it is the improvement teams build on past
work so that their flow charts and data collection become refined with time.
The fact that first efforts are not as complete as they might be isn’t
important as long as improvement activities continue.
I hope that
this example shows how continuous process improvement with trained and
empowered workers contributes to higher quality work, more motivated and
happier workers and a more effective organization. This is the type of
organization that survives and thrives in today’s competitive global
environment.
I also hope
this example has convinced you to learn statistical process control in more
depth. This example is only an introduction to statistical methods. There are
different types of control charts that are used for different analyses. These
include p charts, np charts, c charts and u charts in addition to the x-bar – R
chart used in the library example. In addition to control charts you need to
know about run charts and scatter diagrams. The Memory Jogger book recommend in
an earlier lecture defines all of these methods.
You may try
statistical methods on simple work processes based on what you have learned in
this lecture. I must caution you that although that may work well you could
cause more problems by trying to apply these simple methods to a process that
demands more complex treatment or different analysis than described here. If
you have access to someone versed in statistical techniques then go ahead and
begin using these techniques but be sure to ask the expert to review your work
to ensure the methods apply to the processes you intend to improve.
Exercise
Since some books and training
courses on statistical process control do not discuss work flow diagrams and
deployment charts you can learn to prepare these tools by practicing on
processes around your home. Develop a flow chart, a work flow diagram and a
deployment chart for the activities you engage in from the time you get up in
the morning to the time you leave for work. If you are married I don’t
recommend trying to get your spouse to change the morning routine based on any
process improvement you identify from your charts. You may be judged as having
gone a bit overboard.
If you find that the pace of blog posts
isn’t compatible with the pace you would
like to maintain in studying this material you can buy the book “The Manager’s Guide for Effective
Leadership” in hard copy or for
Kindle at:
or hard copy or for nook at:
or hard copy or E-book at:
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