The Seven Basic Tools
of Quality
These
are the “must” list for SPC programs. Anyone installing and using an SPC program
will use most of these seven tools.
1. Flowcharts –
A pictorial (graphical) representation of the process flow – showing the
process inputs, activities, and outputs in the order in which they occur.
2. Checksheets – A list of
items inspected (checked). The list is usually organized in a standardized
format designed to facilitate information gathering and, later, quantitative
analysis. It also assures that different people will collect required information
in the same way.
3. Histograms
– A graphical
summary of variation in a set of data. A pictorial means of organizing, summarizing,
analyzing, and displaying data.
4. ParetoAnalysis – Uses a
specially organized histogram (the Pareto chart) to provide a picture that
instantly identifies those problem of greatest concern – those problems that should
be addressed first.
5. Cause and effect diagram –
As the name implies, this tool is just a tool of causes and effects diagrammed
to show the interrelationships. The diagram is a form of tree diagram on its
side so that it looks like a fishbone. It is also called Ishikawa diagram after
the man who invented it.
6. Scatter
diagram –
Cartesian coordinate type (X,Y graphs) that illustrate cause and effect
relationships between two types of data.
7. Control
Charts – Graphs of
one or more important characteristics of a product. They are statistical techniques
to analyze the process, and to provide information for correction and
improvement of the process, and thus the products produced on that process.
Seven new quality tools
1. Affinity diagrams –
The affinity diagram is a visual tool that allows an individual or a team to
group a large number of ideas, issues, observations or items into categories
for further analysis. The tool groups the ideas in a way that allows those with
natural relationships or relevance to be placed together in the same group or
category.
2. Arrow Diagrams -
The arrow diagram—also known as activity diagram, network diagram, activity chart,
node diagram or critical path method chart—is used to illustrate the order of
activities of a process or project. Makes use of program evaluation review
technique (PERT) and the critical path method (CPM)
3. Matrix diagram –
Analysis relations between two different factors. Also used in developing
customer requirements into design requirements, then into vendor or purchasing
requirements, and then into production requirements (In this form it is also
called as Quality Function Deployment – QFD - Diagram)
4. Matrix Data analysis diagram – Applies quantitative analysis
to the matrix diagram.
5. Process decision program chart (PDPC) – Used to guide the
implementation process. It organizes each possible chain of events in a complex
plan so that all possible events are identified and planned. For instance, anything that can possibly can
go wrong will be identified, and a plan, and resources, already formulated in
case any of these problem occur.
6. Relations Diagram –
(Also called the interrelationship diagram). Analyses the interrelationships of
complex systems, i.e., which portions of the system relate to which other portions,
and how and to what extent.
7. Tree Diagram - A tree diagram allows you to
detail a conceptual or high level goal into more operational tasks to achieve
the desired result. The tree diagram starts with one item that branch into two
or more branches, each of which branches into two or more, and so on.
Reference used : Book " Statistical Process Control" By Leonard A. Doty
ASQ Quality Progress Magazine April 2012 edition
