
A fixed set of graphical techniques
identified as being most helpful in
troubleshooting issues related to quality

Suitable for troubleshooting most qualityrelated problems, and require little
formal training in statistics
 Ishikawa
(fishbone) diagram
 Check sheet
 Control chart
 Histogram
 Pareto chart
 Scatter diagram
 Flowchart/Flowmap

Popularized by Kaoru Ishikawa:
pioneered quality management
processes in Kawasaki Shipyards

A.K.A cause-and effect diagram,
herringbone/fishbone diagram

Used to demonstrate cause of a specific
event

Used mainly in product design and quality
defect prevention, can also be used
retrospectively

Causes grouped into major categories: 6M’s
Manpower: Anyone involved with the process
Methods: How process is performed and
requirements for doing it, i.e. policies,
procedures, rules.
Machines: equipment, computers, tools, etc.
Materials: Raw materials, parts used to
produce final product
Measurements: Data generated from process
that are used to evaluate its quality
Environment (Milieu) conditions, such as
location, time, temperature, and culture in
which process operates
IHI.ORG
A Fishbone Diagram was famously used prior to the
manufacture of the Mazda Miata, which went on to
be the best-selling 2 seat roaster in HISTORY!!
Make a Fishbone Diagram about the
reasons why you think the ER always seems
overcrowded using the ‘6M’ approach. Be
as detailed as you can, listing as many
causes as possible under the six categories
Note to instructor: There is a Fishbone template MS Word file
in Sharepoint

A tally sheet to collect data on frequency
of occurrence

Used when data can be observed and
collected repeatedly by either the same
person or the same location

Effective tool when collecting data on
frequency and identifying patterns of
events, problems, defects, and defect
location, and for identifying defect causes.
Number of people in wait line at Registration Desk
This helps to
determine
staffing needs
and size of
waiting room

Pioneered by Walter
Shewhart who worked at
Bell Labs in the 1920’s

Helped to improve the
reliability of the telephone
transmission system at Bell





Chronological plot of measurements of important
variables
Upper and lower reference thresholds called control
limits (3 Std. Deviations from Mean) are plotted:
define natural range of variation within which plotted
points should fall
Any points falling outside of control limits may
indicate that all data were not produced by the
same process, either because of lack of
standardization or a change in the process may have
occurred
Such changes could represent either quality
improvement or quality deterioration, depending on
which control limit is crossed
Useful both for monitoring if processes get worse and
for testing and verifying improvement ideas
http://www.coe.neu.edu/healthcare/pdfs/publications/C13-Use_of_Control_C.pdf
Upper & lower control
limits indicate threshold
at which process output
is considered
statistically 'unlikely' ;
drawn 3 std. errors from
the centre line
i.e. mean of
the variables
Sometimes ‘warning
lines are drawn 2
std. errors from
center line
In 2005, the Robert Wood Johnson Hospital won the Malcolm Baldrige National
Quality Award. Currently their ER LOS is 38 minutes for a discharged patient and
90 minutes for an admitted patient. They offer a 15-30 minute guarantee: see a
nurse in 15 minutes and a doctor in 30. The quicker response time and LOS in
their ER has brought increasing revenues each year, and another wing had to
be added to the hospital to accommodate their ER admissions.
This is a hyperlink to an excellent video on how to make a
statistical control chart on MS excel
http://www.youtube.com/watch?v=uGgd3iiQrUI
Introduced by Karl Pearson,
the father of mathematical
statistics
 Etymology uncertain. Said to be derived
from the Greek histos 'anything set
upright' and gramma 'drawing, record,
writing‘
 It is also said that Karl Pearson, who
introduced the term in 1895, derived the
name from "historical diagram".


Frequency distribution shows how often each
different value in a data set occurs

A histogram is the most commonly used graph
to show frequency distributions (next slide)

Looks like a bar chart, but used for continuous
data(as opposed to categorical data)
HISTOGRAM
Continuous data, so there are
no spaces in between the bars
Data collected into
categories of width 30 LB
Your preceptor will assign you a task
involving data collection and using an
MS Excel template to create a histogram
Concept introduced by
Vilfredo Pareto, mathematician
and economist
 Built on observations of his such as that
80% of the land in Italy was owned by
20% of the population
 The purpose is to highlight the most
important among a (typically large) set
of factors causing defects/delays

Lt. vertical axis:
Frequency of
occurrence
Rt. vertical axis:
cumulative
percentage of total
number of
occurrences,
GO AFTER THE 2 OR 3 MOST
IMPORTANT FACTORS TO GET
THE DESIRED RESULTS
CRITICAL FEW
TRIVIAL MANY
This is a hyperlink to a video on how to make a
Pareto Chart on MS excel
http://www.youtube.com/watch?v=TBtGI2z8V48
› When trying to identify potential
root causes of problems.
› After brainstorming causes and effects using
a fishbone diagram, to determine
objectively whether a particular cause and
effect are related
› Pairs of data where a relationship is suspected
are plotted on the X axis(independent variable)
and Y axis(dependent variable)
› First described by Sir Francis Galton, English
Mathematician(cousin of Darwin)
TYPES OF RELATIONSHIPS BETWEEN THE
VARIABLES
Pairs of data where a relationship is suspected are
plotted on the X axis(independent variable) and Y
axis(dependent variable)
DEPENDENT VARIABLE
There is a negative correlation between
years of experience of MRI Techs and rate
of repeat MRI scans(no surprise here!)
IINDEPENDENT VARIABLE
This is a link to a video on how to make a
scatter plot in MS Excel
http://www.youtube.com/watch?v=bYf6q
O-iBW0
Pioneered by Frank Gilbreth,
Inspiration for the movie
Cheaper by the Dozen
 Diagram that represents a
process, showing steps as boxes
of various kinds, and their order by
connecting them with arrows
 Used in analyzing, designing,
documenting or managing a process

START/STOP BOX
DECISION DIAMOND
PROCESS BOX
CONNECTING
ARROWS DETERMINE
ORDER OF PROCESS
Note: There will be a dedicated session on
workflow mapping