7 QC TOOLS: FISHBONE DIAGRAM

 

WHAT ARE 7 QC TOOLS AND HOW THEY ARE USED DURING WORKING?

·         These seven basic tools of quality, first emphasized by Kaoru Ishikawa, a professor of engineering at Tokyo University and the father of "quality circles."

·         Start your quality journey by mastering these tools.

·         Below are 7 quality tools explained in brief.

·         Cause and effect diagrams (also called Ishikawa or fishbone diagrams): It Identifies many possible causes for an effect or problem and sorts ideas into useful categories

·         Check sheet: It is the sheet which contains all possible parameters mentioned to be checked before further action on that product or part.

·         Control charts: This are the characteristic charts which gives information about the measured parameters deviation with respect to the standard parameters.

·         Histogram: The most commonly used graph for showing frequency distributions, or how often each different value in a set of data occurs.

·         Pareto chart: A bar graph that shows which factors are more significant.

·         Scattered diagram: It is the Graphs pairs of numerical data, one variable on each axis, to look for a relationship.

·         Stratification: It is a technique that separates data gathered from a variety of sources so that patterns can be seen.

CAUSE AND EFFECT DIAGRAM

·         It was devised by Professor Kaoru Ishikawa in 1960.

·         The technique was then publish in 1990 in his book “Introduction to quality control”

·         Also called Ishikawa or fishbone diagrams.

·         This technique is used to discover the root cause of a problem, identifies where and why a process is not working properly.

·         It is also known as fishbone diagram, Ishikawa diagrams, Herringbone diagram and fishikawa diagrams.

TECHNIQUE

It is the technique which Identifies many possible causes for an effect or problem and sorts an ideas into useful categories.

ADVANTAGES

·         It used to find out root cause of any problem using some structural tool.

·         It confirms the any process in the company is doing well or not.

·         It indicate the maximum possible cause of problem in the process by using we can reduce the causes and improve our working process.

·         It identifies the area from which data should be collected for analysis of process.

 STEPS TO USE THIS TECHNIQUE

Identify the problem

·         Select the particular problem.

·         Identify who is involve in this problem.

·         When and where it occurs.

·         Problem should be very specific and well defined in such a way that everyone who involve in this should understand what is the problem being analysed.

·         Write the proper problem definition at the top of the diagram.

Brainstorm

·         It is the method of applying multiple people’s skill for multiple days to see the same problem or same process with different ideas.

·         Like there is a process and we have to find out the problem in that process, then create a team from different departments.

·         The team is built in such a way that those persons in the team are not seen this process too closely, that means fresh eye peoples.

·         One by one send to see the process for a specific timing and when he come back then note his observations for that process in a particular time, this process is continue for a whole team members.

·         Again same process with different time span for different people in the team is carried on next day or day by day and again note their observations.

Let me explain it by an example

·         There is a process of shot blasting need to be taken for brain storming.

·         I have a team of 10 peoples of names are A,B,C,…..J. who are not working on shot blasting process that means the shot blasting process is new for them.

·         Now select a day for observation.

·         On that day start the process of blasting and sent A into booth for observation for 15 min after starting the process.

·         Again after 15 min next people B is gone in blasting booth and A is come with some observations.

·         Noted all observations of all peoples and do for the same for next day only change their sequence that means at the starting of process on next day the people except A is go into the booth.

·         It is very important to brainstorm before going for cause analysis.

Identify the possible cause

·         Maximum possible causes are as follow

·         Man, Machine, Material, Method, Measurement, Environment, etc.

·         Mention all the possible causes as a bones of fish in the fishbone diagram.

·         If any sub-causes are involve in the main cause then mark it by narrow lines.

Analysis of Fishbone diagram

·         In this section all possible causes are analysed and defined each cause complexity and importance in the problem.

·         That means sorting out the main causes and sub causes.

·         We can investigate the most likely causes may occurs further in this process.

·         Analysis gives us most probable causes of the problem due to which our process is not doing proper work.

·         There are 4P & 6M formula for defining causes

·         For any service industry 4P are Policy, People, Procedure, Plant.

·         For manufacturing industry 6M are Man, Material, Machine, Method, Measurement and Mother Nature (Environment).