Quality tools are the heart of the management activities

1. Seven Statistical Tools Of
Quality

2. Tools and their uses
S.No Statistical tools Purpose
1 Flow chart For depicting the essential steps of a process by
using standard symbols
2 Check sheet For systematic data gathering, by tabulating the
frequency of occurrence
3 Histogram For graphically displaying the frequency
distribution of the numerical data
4 Pareto diagram For identifying the vital few causes that account
for a dominant share of a quality loss
5 Cause and effect diagram For identifying and analysing the potential causes
of a given problem
6 Scatter diagram For depicting the relationship between two
variables
7 Control chart For identifying process variations and signalling
corrective action to be taken

3. Relationship between QC tools and PDCA cycle
S.No Q-7 Tools Plan (P) Do (D) Check (C) Act (A)
1 Flow chart x X X X
2 Check sheet X X
3 Histogram X X X
4 Pareto diagram X X X
5 Cause and effect diagram X X X
6 Scatter diagram X X
7 Control chart X x

4. Flow charts
• It is used for depicting the steps of a process in an easily understandable form, by using standard
symbols
• It is used to document and analyse the connection and sequence of events in a process
S.No Symbol Name Meaning
1 Terminator
For indicating chart start or
end of the flow chart
2
Action
(rectangular)
For identifying a process or
activity or task or operation
3 Decision For indicating a decision
4 Arrows
For indicating the direction
of the process
5 Link
For indicating a link to
another page or another
flow chart

5. CHECK SHEET
• Definitions:
• Check sheets are tools for collecting data. They are designed
specific to the type of data to be collected. Check sheets aid
in systematic collection of data.
• Examples:
• Daily maintenance check sheets, attendance records,
production log books, etc.
• Function:
• To check the shape of the probability distribution of a
process.
• To quantify defects by type.
• To quantify defects by location.
• To quantify defects by cause (machine, worker).
• To keep track of the completion of steps in a multistep
procedure (in other words, as a checklist).

6. HISTOGRAM
Definition:
• Histograms or Frequency Distribution Diagrams
are bar charts showing the distribution pattern of
observations grouped in convenient class
intervals and arranged in order of magnitude.
Histograms are useful in studying patterns of
distribution and in drawing conclusions about
the process based on the pattern.
Benefits:
• Shows the number of values within an interval
and not the actual values.
• Graph huge data sets easily with histograms.
• Change of interval in histogram is possible to
see which gives a better description of the data.

7. PARETO DIAGRAM
Definition:
• Pareto Diagram is a tool that arranges items in the order of the magnitude of their
contribution, thereby identifying a few items exerting maximum influence.
Benefits:
• Prioritize projects for improvement,
• Set up corrective action teams to solve problems,
• Identify products on which most complaints are received,
• Identify the nature of complaints occurring most often,
• Identify most frequent causes for rejections or for other
similar purposes.

8. CAUSE & EFFECT DIAGRAM
Definition:
A diagram that shows the causes of an event
and is often used to outline the different steps in a
process, demonstrate where quality control issues
might arise and determine which resources are
required at specific times.
The 5 Ms Machine (technology)
• Method (process)
• Material (Includes Raw Material, Consumables
and Information.)
• Man Power (physical work)/ Mind)
• Measurement (Inspection)

9. Definition:
• A scatter diagram, also called a scatterplot or a scatter plot, is a visualization of the relationship
between two variables measured on the same set of individuals.
• A tool to study the relationship between two variables is known as Scatter Diagram. It consists of
plotting a series of points representing several observations on a graph in which one variable is
on X-axis and the other variable in on Y-axis.
Benefits:
• It shows the relationship between two variables.
• It is the best method to show a non-linear pattern.
• The range of data flow, i.e. maximum and minimum
value, can be easily determined.
• Shows a trend in the data relationship
• Retains exact data values and sample size
• Shows minimum/maximum
SCATTER DIAGRAM

10. CONTROL CHARTS
Definition:
• Control chart makes possible the diagnosis and correction of many
production troubles and brings substantial improvements in the quality of
the products and reduction of spoilage and rework.
• Variability is inherent in all manufacturing processes. These variations may be
due to two causes
• Random / Chance causes (un-preventable).
• Assignable causes (preventable).
Benefits:
• Control ongoing processes by finding and
correcting problems.
• Predict the expected range of outcomes.
• Determine whether a process is stable

11. GRAPHS
Definition:
• Graphs of various types are used for pictorial representation of data. A
diagram showing the relation between variable quantities, typically of
two variables, each measured along one of a pair of axes at right
angles.
Types and Purpose of Graphs:
Sl.no Graph
Type
Purpose
1. Bar Graph To compare sizes of data
2. Line Graph To represent changes of data
3. Gantt Chart To plan and schedule
4. Radar chart To represent changes in data
5. Band Graph To represent changes in data

12. THANK YOU