seven old tools of quality management
DESCRIPTION
Seven QC Tools Flow Charts Check Sheets Histograms Pareto Diagrams Cause and Effect Diagrams Scatter diagrams Control Charts To analyze Quantitative DataTRANSCRIPT
Seven Old Tools of Quality Management
Dr. Mohamed RiyazhKhan - DoMS Seven QC Tools Flow Charts Check
Sheets Histograms Pareto Diagrams
Cause and Effect Diagrams Scatter diagrams Control Charts To
analyze Quantitative Data Flow Chart A Flow chart or Process map
identifies the sequence of activities or the flow of materials and
information in a process. Help the people involved in the process
understand it better and more objectively by providing a picture of
steps needed to accomplish a task. Flow charts are best developed
by having the people involved in the process employees,
supervisors, managers and customers. Once constructed, it can be
used to identify quality problems as well as areas for productivity
improvement Check Sheets Check Sheets are special types of data
collection forms in which the results may be interpreted on the
form directly without any additional processing. Histograms
Histograms provide clues about the characteristics of the parent
population from which a sample is taken. Patterns that should be
difficult to see in an ordinary table of numbers become apparent.
Pareto Diagram A Pareto diagram is one in which the characteristics
observed are ordered from largest frequency to smallest. This is
based on the principle of an Italian economist Vilfredo Pareto.( ).
He observed during his study on the distribution of wealth that 80%
of the wealth is owned by 20% of population. For example, -80% of
money is spent on 20% of machines and materials. -80% of defects
one due to 20% of causes (root causes) -80% of problems in a
society come form 20% of people -80% of sales due to 20% of
customers. -80% of complaints due to 20% defects. No. % Dimensional
Error Geometrical error Surface scratch Surface finish 9 6 42 3 15
10 70 5 60 100 PARETO DIAGRAM A. Dimensional Error 9 9 B.
Geometrical error 6 6
PARETO DIAGRAM A. Dimensional Error B. Geometrical error C. Surface
scratch D. Surface finish C A B D A B C D Before Solving the
problem After Solving the problem Construction of a Pareto
diagram
Determine the methods ofclassifying the data by problem, cause,
non- conformity etc, Decide the factors to be used to rank
thecharacteristics Collect data an appropriate time interval
Summaries the data and rank orderfrom largest to smallest
(descending order) Constructthe diagram and find the vital few
Compute the cumulative values in number and percentage and plot the
cumulative curve. After solving a problem, repeat steps 4 through 6
and compare the diagrams and measure the percentage improvements
Cause and Effect Diagram
It is a simple graphical method for presenting a chain of causes
and effects and so for sorting out causes and organizing
relationships between variables. Introduced by Kaoru Ishikawa in
Japan, so called as Ishikawa diagram. Because of its structure it
is called as Fishbone diagram. CAUSE AND EFFECT DIAGRAM
. METHOD MAN STORE BIN ARRANGMENT CARELESSNESS TRANSPORT SCRATCH
SOFT WORK HOLDING MEASURMENT MATERIAL MACHINE CAUSE AND EFFECT
DIAGRAM The diagrams are useful to :
Analyze actual conditions for the purpose of productor service
quality improvement, more efficient use of resources and reduced
costs. Eliminate conditions causing nonconformities and customer
complaints. Standardize existing and proposed operations. Educate
and train personnel in decision making and corrective action
activities. Scatter Diagrams A scatter diagram is graphical
representation of relationship between two variables, one variable
is called independent variable, and the other is called dependent
variable.