Jump to content
Message added by Mayank Gupta,

CEDAC (Cause and Effect Diagram with Addition of Cards) is a modified fishbone diagram where both causes and solutions are brainstormed simultaneously. Causes are listed on post it notes (called as cards) and pasted on the left of the line while solutions are listed on a different colored post it notes and pasted on the right.


An application-oriented question on the topic along with responses can be seen below. The best answer was provided by Rajesh Chakrabarty on 16th Mar 2021.


Applause for all the respondents - Mohamed Asif, Sundeep Kailwoo, R Rajesh, Rajesh Chakrabarty


Also review the answer provided by Mr Venugopal R, Benchmark Six Sigma's in-house expert.


Q 347. CEDAC is an enhancement to fishbone diagram and it can help target the right problems, involve the right stakeholders in problem solving and ensure that solutions work. What is CEDAC? Explain its working with an example.



Note for website visitors - Two questions are asked every week on this platform. One on Tuesday and the other on Friday.

Link to comment
Share on other sites

6 answers to this question

Recommended Posts

  • 0

CEDAC stands for Cause and Effect Diagram with the Addition of Cards. It was developed by Dr. Ryuji Fukuda, at Sumitomo Electric, as a tool for continuous systematic improvement.

The CEDAC board helped to identify causes of specific problems and to identify, test and institute process improvement in a participatory approach. 350 CEDAC projects were initiated, tried and tested by Sumitomo Electric with extraordinary results. It was proven to be an effective tool and the concept was appreciated as it could be applied to a variety of situations – Design problems, Communication Problems, Set Up Problems, downtime problems and many other problems an organization faces regularly and commonly. Today the concept is used in many organisations which believe in participatory approach and development of solutions for any problem at the helm of the workplace.

How Does a CEDAC work??

It is apt to say that CEDAC is an enhancement of the Fishbone diagram, which accentuates the process that allows team members to build on each other’s ideas from a brainstorming session.

<Diagram 1>

1)      The team should agree on a problem to be analysed and solved- <Diagram 1> is a CEDAC board for the problem of Hitrate of on time food delivery

2)      Determine the major categories which can be cause or have effect on the problem

3)      Think of possible causes in each category and jot them in sticky notes (Post it stickers) and stick them on the CADEC Board in the blue zone (Left Side) in each Category box

4)      Use the “5 Whys” tool to search for root causes and jot them on the sticky notes and connect them to the various other contributing factors.

5)      This board can be placed like a bulletin board at the “Gemba” with an invitation for the whole team to examine and possibly add some more causes that they feel are relevant for the problem statement.

6)      The team should be encouraged to also post their ideas of solution for the causes of the problems, on the Yellow zone for respective categories (right side) of the line. 

** Sticky note pads of both colors need to be made available**


The above six steps ensure that the causes and solutions keep coming in tandems. The solutions need to be analyzed for the impact and effect and prioritized based upon the maximum benefit. The idea is to implement the solutions and reduce & eliminate the causes that impact the problem statement.

The Board needs to be updated as and when a cause reduces.

The status of performance improvement also need to be updated. This way the activity has an immediate feedback mechanism. This improves the motivation for participation.


The above method was implemented in an organization, by me, wherein food delivery was a channel for sale. It is common knowledge that “Timely Delivery” is the most important deliverable for the customer to appreciate the transaction, followed by Quality of appearance, taste etc. The fact is that in most of the food products, the time spent in delivery also impacts the quality of food negatively in direct proportion.

Hence, the problem statement was about Hitrate of Delivery (percentage of orders delivered within the stipulated and committed time of 30 minutes). Internally the objective was to close the order within 30 minutes, ie. The rider would return to the outlet after completing a single order within 30 minutes- That would confirm that the customer has received the order within 30 minutes.

The CADEC approach was applied in 5 sample outlets- The idea was that the most common and effective learnings would be applied across all the outlets during a roll out. The impactful Insights that were derived from the CEDAC Board were:







- Non availability of Riders
- New Riders took longer to reach the Customer as lack of area knowledge

- Incentive on attendance and productivity
- Soft copies of maps were developed with area land marks


Trading Area

- Trading area was not defined- distance of delivery was very high in many orders which took lot of time , and consequently the orders pending for delivery also got delayed

- Trading area was rationalised to a seven minutes riding distance during peak traffic times. This actually ensured that we were able to deliver food to the customers on time and the repeat business grew after a period of time.


Design of Outlet & Process

- The Delivery section was too far from the Exit it took that much time more.
- The Bike parking area was too Far from the Exit
- Orders of delivery took more time to prepare as the home delivery orders are mostly of units of product

- Special section was created for delivery where the 5S approach was followed to improve efficiency.
- Bike Parking and maintenance  was given due diligence
- Orders for delivery were given priority and the 5S approach at the Delivery section helped a lot in saving time for production, assembly and packaging of the orders

- Large orders with more than 15 units of products were given separate status as "High value orders and the delivery time was extended and conveyed to the customer. This reduced the customer's anxiety.


IT & Equipments

- There was no method to confirm the actual delivery time of the order
- Bikes and kitchen equipments needed to be upgraded

- Applications were developed to ensure that riders could update the delivery and payment times.
- Rider tracking GPS was incorporated in the application
- Bikes and equipments were upgraded with a proper preventive maintenance calendar in place



- Customer Data base was not very neat with address information being incorrect
- Customers would take time to receive order or make payment , thereby delaying the rider for the pickup/ delivery of next order

- Existing Customers were called and addresses were rectified. A standard format of registration for address was instituted. Order takers were trained to follow the address confirmation process and entry in the Delivery software.
- Customers were sent messages on phone in advance before the rider reached them, to remind them to keep the payment handy


 The results were nothing less than awesome. We not only saw an excellent Hitrate , but also a steady growth in orders and revenue- a brand revival !!

Some points that we have to take note of;

-          Ensure that all members participate in some way or other and no one is allowed to overpower anybody’s opinion in any way- it has to be a receptive process

-          A “NO BLAME” atmosphere with mutual respect needs to be instituted.

-          Categories must be defined well within the team and ideas beyond the defined categories should also be given due respect- “Only an unshared idea is a bad idea, else no shared idea is bad”

Some other benefits that were realised.

-          Team Bonding

-          The team learnt a constructive approach to resolve issues

-          We realized the potential of some people from within the team- we had such wonderful people who were prospective leaders of the future.

This was one of the best projects I have led and the CEDAC approach was the inspiration and method behind it.

Diagram 1 - CEDAC Board.png

Link to comment
Share on other sites

  • 1

Benchmark Six Sigma Expert View by Venugopal R

The Fishbone diagram, which is also known as ‘Cause & Effect Diagram’ or Ishikawa diagram is a very popular tool used for identifying potential root causes. Most Busines Excellence professionals will need no introduction to this tool which is very widely used. The fishbone diagram leaves us with a list of potential root causes (also referred to as X factors) stratified under few headings.


Dr. Ryuji Fukuda developed the method known as CEDAC, which is an acronym for ‘Cause and Effect Diagram with the Addition of Cards’. In this method, each participant is asked to identify the causes for a problem independently and write it on a post-it sticker. The recommended approach is to ask as question ‘Why not?’ (i.e. why do we consider as the constraints to achieve our target?) and identify the possible reasons.


All the stickers are collected and grouped as done in an Affinity diagram and then transferred to the fishbone diagram in the CEDAC board, under the appropriate category. These stickers are stuck on the left side of the ‘bones’ of the fishbone diagram. It may be observed that the method adopted may be considered as a ‘modified Affinity Diagram’.


Once all the stickers with the causes are stuck on the CEDAC board, the each team member is asked to view all the causes and identify solution(s) for each cause. They will write the solutions in another ‘post-it sticker’, of a different colour. This time, these stickers are stuck on the right side of the bones containing the corresponding causes on its left side.


The solutions are evaluated by the team and the ones that get shortlisted are shown on the upper right corner of the CEDAC board, as ‘New Standards’.




The CEDAC board also houses the Problem statement (Problem Effect) and the Goal Statement (Target Effect). An appropriate chart, such as a trend chart is also included to help monitor the progress based on the implementation of the finalized solutions.


Thus, unlike the traditional Fishbone diagram, which is useful for the Causal analysis, he CEDAC becomes a tool for solution implementation as well as tracking the progress of the target effect.

Link to comment
Share on other sites

  • 0

CEDAC is Cause and Effect Diagram with the Addition of Cards - A Tool for Continuous Systematic Improvement introduced by Ryuji Fukuda.


Dr. Fukuda effectively integrated various “Japanese techniques” like


Hoshin Kanri,


with the “Traditional Knowledge” of Industrial Engineering, Statistical Process Control & Reliability and developed powerful tools such as,

SEDAC - Structure for Enhancing Daily Activities through Creativity

P/O matrix - Tool for Policy Deployment and

On Error Training, Window Analysis & Stockless Production.


CEDAC is a visual, team-oriented problem-solving tool which is a substantial improvement to the Ishikawa diagram. It outlines a structured method to work together, collect facts and define causes of a problem, then generate, document and systematically test out associated improvement ideas.  


CEDAC can be used on any problem that needs improvement, not only to those related to Quality Control.


Idea generation and brainstorming is done during the meet, as well as outside of the meeting rooms, these ideas are collected on small cards. Cards are also used to gather inputs from employees who are not in the group and typically can be used/distributed with anyone who is involved in the Process.


Here, the Improvement activity is promoted by Three Driving Forces, viz.,

Developing Reliable System

Creating a Favorable Environment

Practicing Together



Proactively asking the below questions during the start of the project can ensure effectiveness of the plan. Questions such as,

Do we have a Reliable System?

Is the Environment favorable?

Have the team members practiced the System enough?


Below diagram is the summary view of CEDAC System


Conventional quality tools assemble and integrates disorganized data into meaningful data points and to ease improvements Implementing countermeasures, confirming the results, standardizing and adhering to standards are essential.


CEDAC system consists of three processes:

  • Window Analysis (1st Stage)
  • CEDAC Diagram (2nd Stage)
  • Window Development (3rd Stage)

Window Analysis - (1st Stage):

This is used to determine potential root cause(s) of a problem.

An extension to Johari’s Window Model.

Selecting combination of Party X and Party Y is critical, depending upon the complexity of the problem it is decided.

This technique questions any 2 parties, if a practice, process, or a set of work instructions is known and practiced in order to avert or minimize performance problems.


This window enables to discover how functions are interacting, communicating and exposing gaps in understanding and process knowledge, from general to specific.


Based on the scenario used, typical inference from the model could be as listed below,

Company directives are followed.

Company directives are not always followed.

Company directives were not communicated to some parties.

Company directives need to be communicated to make information available to all parties.


These 4 categories can be summarized as below


Description of the event

Nature of the situation


Established – Known – Practiced

Ideal situation


Established – Known – Unpracticed

Problem with practice


Established – Unknown – Unpracticed

Problem with communication


Not established – Unknown – Unpracticed

Problem with standardization


CEDAC Diagram - (2nd Stage):

Fishbone diagram is used examine the cause of the problem

Improvement Cards are used to figure out different ways of improving the process. Cards are of two types, fact cards and solution cards (placed next to the fact cards). Fact cards list the facts. Solutions cards list the generated ideas.

Visual quantification is done by using charts to fix the target and monitor the progress.


Based on analysis, solution cards are shortlisted and evaluated. Test results are studied carefully.

“Dot System” is used in each possible solution to bucketize the solutions.

Single dot (•) – the idea is of interest

Two dots (••) – the idea is under the preparation

Three dots (•••) – the idea is under the test

Based on Dot system, ideas are implemented in the process.


Window Development - (3rd Stage):

This inspects the actions of CEDAC diagram and emphases on new standard compliance. So that each employee must understand the new standards clearly without ambiguity. Here numerical methods are used to appraise the effectiveness of the new standard.


CEDAC is extensively used to improve and engage employee involvement in the organization. 

Typical applications include that of,

For Production & Services
• Lead Time Reduction in production & services
• Inventory Reduction
• Reducing Rework / Scrap / Errors
• Increasing Yield
• Reducing Time and Cost Overruns in projects
• Cost Reduction
For Administration / Sales Offices
• Reduce Late coming / Absenteeism
• Speedy recovery of receivables
• Increase Orders to Enquiries ratio


To summarize, CEDAC,

  • Orients all the members of the organization, directs their actions by graphically presenting the project, and allows them to successfully contribute to the improvement process.
  • Allows sharing of essential information with all associates, thus promoting autonomous actions.
  • Encourages all individuals in the organization to use their strengths.
  • Elevates chances to generate ideas that enable progress even by at least half a step, as it makes the members keep thinking.
  • Integrates external knowledge and the member’s knowledge to create new ideas and technology.
  • Standardizes thoughts and ideas with favorable test results and accumulates them as intrinsic and management technology.
Link to comment
Share on other sites

  • 0

CEDAC is a modification to the Cause and Effect Diagram, with addition of Cards, hence the name Cause and Effect Diagram Adding Cards (CEDAC). As the name suggests the process involves adding Cards to a typical cause and effect diagram construction exercise, these cards are typically 3X5 (cm) in size or post-it notes. This approach elaborates on the original process and involves the inclusion of ideas, opportunities outside the functional team, where many more members from related processes and departments can be asked to participate in the brainstorming exercise to share their ideas while the Fishbone diagram is being constructed.

This method was developed by Sumitomo Electric Industries of Japan in 1978. 

Just like CED, CEDAC also focuses on identifying the major and minor bones (causes leading to an effect) but also incorporates identifying the workflow analysis, creating a countermeasures matrix, identifying the possible multicollinearity factors. This is where the significance of CEDAC gains over CED, but not all situations and projects may need a CEDAC Vs a CED as CEDAC is more time consuming, wants more efforts and involvement, may mislead the original ask with the involvement of too many inputs. One has to be very judicious to apply CEDAC where it demands an application.

An Example where deploying CEDAC would provide practical value add inputs, could be an Employee Turnover project, which may be impacting a particular account, where the project is initiated, but when we look at the Upstream and downstream processes, which may impact an employees attrition from an organization, we may not want to operate in a Silo but involve cross functions teams, when we are in analyze phase of the project and start working on root cause identification using CED. This is one such situation where deploying CEDAC would make a valuable impact on the project across accounts and the organization in general.

Elaborating on the Example above how inputs from various other functions may be helpful in CEDAC:

An Account is facing issues with high Attrition ( employee turnover ) rate, Operations along with the Continuous Improvement team starts with Creating the CED initially to identify the major Bones ( Man, Machine, Method, Measurement, Material, and Mother Nature ) and start growing the minor bones of the CED. But it recognizes that Human Resources Team that is involved in Hiring these resources are required to provide their inputs in terms of the challenges and the opportunities they see in the hiring process for this campaign, Need to involve the Learning and Development team responsible for Training the hired resources and IT Team (Given that most of the Processes are Work From Home now) to also seek their observations during onboarding the candidates for the Campaign. Now expanding the scope of brainstorming exercise and seeking inputs from these teams will be better captured through CEDAC.


Why and How the Inputs from these 3 extended functions impact the Overall Employee Retention efforts in long term:


HR Function – Talent Acquisition Team – 
1. They can help the project in identifying the type of profiles that don’t stick to a particular campaign.
2. The challenges they may face to hire from a particular location, may help the organization to see if there is a possibility to hire virtual employees from a better location with a historically low turnover.
3. TA Team can also help project what can be a better demographic fit for a particular campaign and does it makes more sense to do target hiring than look for a generic hiring practice.
4. TA team can provide their inputs while brainstorming on additional factors that Operations and other functions may not have visibility to.

Learning and Development Team – 
1.    Their inputs during the Brainstorming session can help us to identify if the training process and training duration play any part in employee retention, another factor that we may want to look at in 0-30 Days terms, especially during training and Transition periods of an employee in a process.
2.    They can identify that certain employees with certain skills are better suited for a particular type of industry and even though everyone should be trainable on a process unless certain specific skills are mandatory, their inputs can help redefine the job profile, which in turn can help hire employees expected to meet the operational demands of the work and would stick longer with the organization.


IT Team –
1.    With Technology becoming critical in an environment where more and more jobs will be performed Virtually and away from Brick and Motor set up, Employees being encouraged to work on BYOD ( Bring your own device ), IT team will be able to provide their inputs as to what type of employees ( Tech Savvy Vs not great at Troubleshooting for minor issues) may have an impact on people leaving because technology is impacting their performance and are not able to meet the basis IT Expectations when faced with an outage. 
2.    They may be able to provide input on what sort of minimum tech. requirements must be mandatory for a BYOD device to make sure we are able to isolate the cases during the Hiring and Interview stage itself if that candidate would qualify to move into a production environment and we don’t see a fall out due to tech issues after onboarding the candidate.

There may be other functions and situations that are applicable to similar situations, where an output triggers actions across different functions. This is where CEDAC help in identifying the cross-functional actions across different teams, Data integrations between different sources to build a complete picture for a Situation.

Link to comment
Share on other sites

  • 0

CEDAC denotes Cause and Effect with the Addition of CARDS Dr. Ryuji Fukuda. It is a problem solving tool . It helps in brainstorming the problem by encouraging participants to put forth their ideas and come up with solutions The ideas are written generally through cards or some sort of sticky notes. 


How does it work:

1. Ideas/Facts given by participants are placed on the left hand side of each of the categories and probable solutions are kept on the right side of each of the categories.

2. A colour code is provided to differentiate solutions and ideas.


Let us take a practical example as how this can be made useful.


Example1: Imagine a hypothetical scenario. An international cricket match is being played. The batting team management is trying to reason out the situation.The opponent team is asking the Umpire to declare the batsman out.




In the above example, amber box highlights the facts and green coloured boxes provide the potential solutions



Benefits of CEDAC tool:
1. With a systematic analysis of the problem we will be able to get valuable ideas from which potential solutions can be obtained quickly
2. As this tool supports an inclusive approach (of all participants), more ideas will be generated and there is no bias/favoritism shown, while providing/giving ideas

3. Provides Varying solutions often with Quality (as this is done by people who are actually working on the problem)

4. Can be cost effective and provide rapid potential solutions as problems are displayed on the board and against which solutions are being discussed


By using CEDAC, there will be a structured approach in solving a problem. By using this tool, its easy to compare the problems at hand and come up with good and viable solutions at a rapid pace as ideas galore with no restrictions.


Reference Site: For definition -   https://www.leansixsigmadefinition.com/glossary/cedac/

Link to comment
Share on other sites

This topic is now closed to further replies.

  • Who's Online (See full list)

    • There are no registered users currently online
  • Forum Statistics

    • Total Topics
    • Total Posts
  • Member Statistics

    • Total Members
    • Most Online

    Newest Member
  • Create New...