illustrate the use of Cause-and Effect (Ishikawa) Diagram, as a quality improvement tool


Using a hypothetical situation, illustrate the use of Cause-and Effect (Ishikawa) Diagram, as a quality improvement tool

                               NAME                                                    REG. NO.
1.     OLELA OUMA CALVINCE             C12/60277/08
2.     SHARLEEN JEBET CHEBUTUK     C12/60264/08
3.     ANTHONY K. KIRUI                       C12/60146/08
4.     ALEX O. ONGERA                          C12/60107/08
5.     LOURINE BELINDA ATITWA        C12/60272/08
6.     JACKLINE JERONO BIIY                C12/60253/O8
7.     MARY ABURA NGUTA                 C11/60239/08
8.     JOY K.RINGERA                             C11/60880/08
9.     IRINE C.KIPTANUI                         C11/60831/07
10.                   VIOLA J. ROTICH                          C11/60223/08



Total quality management or TQM is an integrative philosophy of management for continuously improving the quality of products and processes.
TQM functions on the premise that the quality of products and processes is the responsibility of everyone who is involved with the creation or consumption of the products or services offered by an organization. In other words, TQM capitalizes on the involvement of management, workforce, suppliers, and even customers, in order to meet or exceed customer expectations. Considering the practices of TQM as discussed in six empirical studies, Cua, McKone, and Schroeder (2001) identified the nine common TQM practices as cross-functional product design, process management, supplier quality management, customer involvement, information and feedback, committed leadership, strategic planning, cross-functional training, and employee involvement.
Quality is important to businesses but can be quite hard to define. A good definition of quality is:
“Quality is about meeting the needs and expectations of customers”
Customers want quality that is appropriate to the price that they are prepared to pay and the level of competition in the market.
Key aspects of quality for the customer include:     
  • Good design – looks and style
  • Good functionality – it does the job well
  • Reliable – acceptable level of breakdowns or failure
  • Consistency
  • Durable – lasts as long as it should
  • Good after sales service
  • Value for money
‘Value for money’ is especially important, because in most markets there is room for products of different overall levels of quality, and the customer must be satisfied that the price fairly reflects the quality.

Why quality is important to a growing business
Good quality helps determine a firm’s success in a number of ways:
  • Customer loyalty – they return, make repeat purchases and recommend the product or service to others.
  • Strong brand reputation for quality
  • Retailers want to stock the product
  • As the product is perceived to be better value for money, it may command a premium price and will become more price inelastic
  • Fewer returns and replacements lead to reduced costs
  • Attracting and retaining good staff
One of the keys to obtaining high quality is to make sure the product or service is designed to fit the firm’s capability to produce it. World class firms are using the concept called concurrent engineering in which operation managers and designers work closely together in the initial phase of product or service design to ensure that the production requirements are synchronized with the process capabilities, the result is much better quality and shorter development time.
The management should be concerned with linking each aspect of quality priced by the customer to inputs, methods and procedures that build a particular attribute into the product. Design drawing shows how product or service should be produced. However, they cannot pinpoint a problem in design that needs to be corrected in order to satisfy a customer’s particular quality concern. One way of identifying such problems is to develop a fishbone diagram.

Cause and Effect Diagram/Fishbone/Ishikawa Diagram
Cause and effect diagram is one of the investigating tools available in Quality Management. It is called cause and effect diagram because there is systematic arrangement of all possible causes which give rise to effect. It is also called Fishbone diagram or Ishikawa diagram. It is fishbone because of its shape. Dr. Kaoru Ishikawa, the well known exponent of Quality Circles (QCs) and an important functionary in the Japanese Union of Scientists and Engineers (JUSE ), is credited with investigating and popularizing its use. The cause-and-effect diagram is a method for analyzing process dispersion. The diagram's purpose is to relate causes and effects. Three basic types: Dispersion analysis, Process classification and cause enumeration. Effect = problem to be resolved, opportunity to be grasped, result to be achieved. It is excellent for capturing team brainstorming output and for filling in from the 'wide picture'. It helps organize and relate factors, providing a sequential view. It also deals with time direction but not quantity. The diagram can become very complex or can be difficult to identify or demonstrate interrelationships.

When you have a serious problem, it's important to explore all of the things that could cause it, before you start to think about a solution. That way you can solve the problem completely, first time round, rather than just addressing part of it and having the problem run on and on. Cause and Effect Analysis gives a useful way of doing this. This diagram-based technique, which combines Brainstorming with a type of Mind Map, pushes you to consider all possible causes of a problem, rather than just the ones that are most obvious.
 Cause and Effect Analysis was devised by Professor Kaoru Ishikawa, a pioneer of quality management, in the 1960s. The technique was then published in his 1990 book, "Introduction to Quality Control."The diagrams that you create with Cause and Effect Analysis are known as Ishikawa Diagrams or Fishbone Diagrams (because a completed diagram can look like the skeleton of a fish).
Cause and Effect Analysis was originally developed as a quality control tool, but you can use the technique just as well in other ways. For instance, you can use it to:
  • Discover the root cause of a problem.
  • Uncover bottlenecks in your processes.
  • Identify where and why a process isn't working.
Before taking up a problem for detailed study, its necessary to list down all the possible causes through brainstorming session so that no important cause is missed out. The causes are then divided into major causes or variables. Generally this variable would come under what is termed as 4ms i.e. man, machine, material, and method. Each of these causes or variables are then divided into sub-causes or sub-variables. All these identified variables or causes together with the sub-causes or sub-variables are put in the form of  a diagram having a resemblance with a fish-bone relating to causes and effects, as shown below;

   Lack training
                              Wrong job assignment                         Price setting not proper

Product not as per        customer requirement
                                                             Manual work


Low maintenance
low quality                       High prices       Faulty machine          




How to Develop Ishikawa Diagram

There are four steps in developing Ishikawa diagram;
  1. Identify the problem.
  2. Work out the major factors involved.
  3. Identify possible causes.
  4. Analyze your diagram.

Step 1: Identify the Problem

First, write down the exact problem you face. Where appropriate, identify who is involved, what the problem is, and when and where it occurs.
Then, write the problem in a box on the left-hand or right-hand side of a large sheet of paper, and draw a line across the paper horizontally from the box. This arrangement, looking like the head and spine of a fish, gives you space to develop ideas.
An airport manager has a problem of Delayed Flight Departure

Delayed Flight Departure

Some people prefer to write the problem on the right-hand side of the piece of paper, and develop ideas in the space to the left. Use whichever approach you feel most comfortable with. It's important to define your problem correctly. CATWOE can help you do this – this asks you to look at the problem from the perspective of Customers, Actors in the process, the Transformation process, the overall World view, the process Owner, and Environmental constraints.
By considering all of these, you can develop a comprehensive understanding of the problem.       

Step 2: Work Out the Major Factors Involved

Next, identify the factors that may be part of the problem. These may be systems and procedures, equipment, materials, external forces, people involved with the problem, and so on.
Try to draw out as many of these as possible. As a starting point, you can use models such as the McKinsey 7S Framework (which offers you Strategy, Structure, Systems, Shared values, Skills, Style and Staff as factors that you can consider) or the 4Ps of Marketing (which offers Product, Place, Price, and Promotion as possible factors).
Brainstorm any other factors that may affect the situation.
Then draw a line off the "spine" of the diagram for each factor, and label each line.
In our example, the manager identifies the following factors, and adds these to his diagram:
  • Personnel
  • Procedures
  • Materials
  • Equipment.
  • Others


Delayed Flight Departure






Step 3: Identify Possible Causes

Now, for each of the factors you considered in step 2, brainstorm possible causes of the problem that may be related to the factor.
Show these possible causes as shorter lines coming off the "bones" of the diagram. Where a cause is large or complex, then it may be best to break it down into sub-causes. Show these as lines coming off each cause line.
For each of the factors he identified in step 2, the manager brainstorms possible causes of the problem, and adds these to his diagram, as shown,

Delayed Flight Departure

                                                                                                                         Gate agents are slow

Aircraft late to gate
                                                                                                                         Few agents

Late arrival
                                                                                                                                             Untrained agents    

                                                                                                                                  Under motivated

Gate occupied
                                                                                                                                                  Poor time-keeping
                                                                                                                                                   Late cabin cleaners
Mechanical Failure
Air Traffic
                                                                                                                                                   Late cabin crew
Late pushback tag
                                                                                                                                                   Late cockpit crew
Desire to Protect Late Passengers
Cut off too Close to Departure time
Acceptance of Late Passengers
Issuance of boarding pass
Confused seat Selection
Checking oversized luggage
Delayed check in Procedure
Weight and Balance Sheet Late
Poor Announcement of Departures
Late Food Service
Late Fuel
Late luggage to aircraft






Step 4: Analyze Your Diagram

By this stage you should have a diagram showing all of the possible causes of the problem that you can think of.
Depending on the complexity and importance of the problem, you can now investigate the most likely causes further. This may involve setting up investigations, carrying out surveys, and so on. These will be designed to test which of these possible causes is actually contributing to the problem.
The manager has now finished his Cause and Effect Analysis. If he hadn't looked at the problem this way, he might have dealt with it by assuming that the officers at the airport were "being difficult."
Instead he thinks that the best approach is to arrange a meeting with the officers. This would allow him to brief the officers fully on the new strategy, and talk through any problems that they may be experiencing.

A useful way to use Cause and Effect Analysis with a team is to write all of the possible causes of the problem down on sticky notes. You can then group similar ones together on the diagram.
This approach is sometimes called CEDAC (Cause and Effect Diagram with Additional Cards) and was developed by Dr. Ryuji Fukuda, a Japanese expert on continuous improvement.
Benefits of Ishikawa Diagram
v  It helps the management team to determine the root causes of a problem or quality characteristic using a structured approach.
v  It encourages group participation and utilizes group knowledge especially during the brainstorming exercise.
v  It indicates possible causes of variations or dispersion in a process.
v  It helps in identifying areas where data should be taken or collected for further study.
v  It also allows the management team to identify and graphically display all the possible causes related to a process, procedure or system failure.

In conclusion, we want to appreciate the fact that Cause and Effect diagram is a very powerful tool in the hands of managers, that if adopted by the managements, the quality issue shall be a thing of the past.

1.     Dale L. Besterfield (2005); Total Quality Management, 6th edition, Pearson Education Inc,London.
2.     Dr. D.D. Shanna (2006);Total Quality Management, Principles and Cases, Pearson Education, New Dellu, India.
3.     John s. Oakland (1998);Total Quality Management, A Route Improving Performance, Butterworth Heinemann.

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