1. Interrelationship Digraphs
In this module we will discuss the Interrelationship Digraph which is one of the 7 management and planning tools addressed in the book The Memory Jogger Plus. The interrelationship digraph, or ID, takes the planning process a step further and maps out the logical or sequential links among related items. Thus, logical patterns among the items become more apparent. By logical I mean that you can apply questions like: “If I do this item, what else among all the other items will happen?” or “Does this item result from any of the other ideas being generated?” The ID thus provides an opportunity for multidirectional thinking; and, in particular, allows one to identify either the root cause or causes, or the key issue or issues, among the many items being considered in a planning process.

2. Core Steps in System & Process Design and Improvement
1. Define Problem or Opportunity (Problem Statement)
5. Justify and Plan the Implementation, Manage Change Process
2. Determine Requirements, Constraints, Gap, and Root Causes
Looking again at the core steps in system and process design and/or improvement, we already covered in step 1 how the affinity diagram and the resulting header cards can help a team in defining the problem or opportunity. Now in step 2 we will address how to determine the requirements and constraints, possible gaps, and the root causes and key issues that need to be known before attempting to generate solutions.
4. Evaluate, Prioritize, and Test Solution Ideas
3. Generate and Design Solutions to Meet Needs

3. Analysis Tools for Step 2: Establish Needs and Causes
Define Needs, Gaps or Causes
Listen to the “Voice of the Customer”
Use Cause and Effect Diagrams.
Determine Root Causes and Key Issues
Ask WHY 5 Times
Use Interrelationship Digraphs
Now looking at the analysis tools for step 2 – establish needs and causes, we see that there are two phases to do so, namely define needs, gaps, or causes, and determine root causes and key issues. For the first phase teams often listen to the voice of the customer to determine needs or gaps. The simple cause and effect diagram is also a common approach to determine possible causes. The cause and effect diagram, however, does not identify which of the possible causes are root causes. Thus in phase 2, the team may use the tool of asking why 5 times to determine root causes. However, the most powerful way to reach team consensus in identifying the root causes of and key issues for solving a problem, is to use the Interrelationship Digraph – the focus of this module.

4. Learning Objectives Upon completing this module, you will be able to:
Understand the purpose and use of the Interrelationship Digraph (ID)
Construct, interpret, and revise an ID
Graphically display the complete pattern of cause and effect relationships within complex sets of issues
Identify root causes and key issues in order to develop effective solutions and action plans
Upon completing this module, you will be able to understand the purpose and use of the ID, know how to construct and interpret and revise an ID, and display the complete pattern of cause and effect relationships within a complex set of issues. This is very useful for identifying root causes in order to develop effective solutions and action plans as part of the overall methodology for continuous improvement and problem solving

5. Interrelationship Digraph
This tool takes complex, multi-variable problems or desired outcomes and explores and displays all of the interrelated factors involved.
It graphically shows the logical (and often causal) relationships between factors.
By definition, the interrelationship digraph takes complex multivariable problems, or desired outcomes, and explodes and displays all of the interrelated factors involved. It graphically shows the logical and often causal relationship between factors. In the figure shown here, each of the circles represents an idea, and the arrows show the relationship between those ideas.

6. Interrelationship Digraph
Allows for “multidirectional” rather than “linear” thinking (“web of causes” not just straight line cause and effect)
Graphically maps out the cause and effect links among all items in complex situations that contains many intertwined factors
Employs the clustering of relationship arrows to indicate the issues/causes that are the most fundamental among all the items
Given its strength in allowing for multidirectional, rather than just linear thinking, the ID is useful to help clarify the causal relationships that exist in complex situations where there are many intertwined factors. And by graphically mapping out cause and effect relationships among all items generated, it clearly identifies the key issues and/or root causes among the ideas. Graphically, the interrelationship digraph employs the clustering of relationship arrows between ideas to indicate the issues or causes that are most fundamental among all the items making up or involved with the problem. Thus, the ID marries cause and effects thinking with the freedom of brainstorming to show interrelationships between causes.

7. When to Use an ID Establish Needs and Causes, where often
An issue is sufficiently complex that the interrelationship between and among ideas is difficult to determine
Numerical data are not available to identify root causes
There is a feeling that the problem under discussion is only a symptom
Root causes must be identified (KEY)
Management teams often use the interrelationship digraph in situations where an issue is sufficiently complex that the interrelationships between and among the ideas are not readily apparent. Furthermore, if numeric data is not available to clearly identify the root causes, and the root causes need to be identified in order to solve the problem, the ID can help the teams identify those causes. Such an investigation is particularly important when there is a feeling that the problem under discussion is only a symptom and the key issues and/or root causes still need to be identified. So, if you are faced with a large number of interrelated issues, where root causes need to be identified, where resources are scarce, and there is ample time to complete the required iterative process involved in doing an ID, reviewing it, modifying it, and reviewing it again, then you have a good situation for a clean and appropriate use of the ID.
When you really need to know the root cause(s) and key issues of a problem

8. Construction Steps Step 1: Assemble the Right Team
Step 2: Agree Upon an Issue/Problem Statement
Step 3: Display the Completed Cards
Step 4: Draw the Relationship Arrows
Step 5: Review and Revise the First Round ID
The Interrelationship Digraph can be constructed using the following 7 simple steps. Since we will discuss these steps in detail in the next few slides, there is no need to read through this summary now, although it’s often useful as a handout for a team new to this process.
Step 6: Select Key Items in the Finalized ID
Step 7: Draw the final ID

9. Construction Steps
1. Assemble the Right Team  Four to Six members  Intimate knowledge of issue 2. Agree Upon an Issue/Problem Statement  Various sources: From Scratch, Affinity Diagram, Cause & Effect Diagram
Step 1 is to assemble the right team. Ideally 4-6 people who have some intimate knowledge of the main issue in order to map out the cause and effect relationships that exist related to the central issue. Step 2 is to agree upon the problem statement or issue to be addressed. This problem statement may be generated from scratch, or it may be the second step from your analysis using an affinity diagram, or a cause and effect diagram, or other sources. A lot of people usually do an affinity diagram followed by the interrelationship digraph, so the problem statement is already developed.

10. Construction Steps 3. Display the Completed Cards
Pre-organized, e.g., by Affinity Diagram headers, plus any additional causes or issues not included in the AD headers
Random Distribution
One by one, e.g., clustered
The third step is to write each possible cause or issue on a card or “Post-it note”. These ideas often come from the headers of the AD, plus any additional causes or issues not included in the AD headers. We then display the cards in a random order on a white board, large sheet of paper, or other media that will allow the team to draw arrows between each of the cards. One could also use a matrix approach to do this, and we will address that approach shortly.

11. Construction Steps A B 4. Draw the Relationship Arrows
 Ask of each card: “Does this card cause/influence any of the other cards displayed?”
 Repeat until all cards considered
 Draw one-way arrows only as the question is repeated
Step 4 is the core step in which the team draws the relationship arrows between the cards. This is done by asking the following question for each card: does this card, A, for example, causes or influence any of the other cards displayed? If A does cause or influence B, an arrow will be drawn from A to B. This is repeated until all the cards are considered, drawing one-way arrows only as the question is repeated. In drawing the arrows, there may be a tendency for a team to ask two questions of each card simultaneously. What does this card cause and which items result in this card? Experience shows, however, that this approach can lead to some confusion. It is better, in my experience, to just repeat the cause outward question for each card. In other words, what does this card cause? Then you will identify all the two-way relationships by default. Also, avoid two-way arrows between cards since two-way arrows lead to an endless loop that doesn’t provide new information. Make a decision as to which item is the major influencer. This is often the most valuable outcome of the discussion. A B

12. Construction Steps Review and Revise the First Round ID
Review by team and non-team members
Individuals indicate changes and opinions on basic causes
Incorporate suggested changes that the teams agrees upon
Once step 4 is completed, the team then reviews and revises the first round of the ID. The review may take place by the team as well as non-team members. At this stage individuals can suggest changes or provide their opinion on the basic causes that have been mapped out in the first round ID. This provides an opportunity to review and incorporate the suggested changes into the ID.

13. Construction Steps Select Key Items in the Finalized ID
Find cards with the highest total # of arrows, then cards with the next highest totals, etc.
Review all cards for those with predominantly outgoing or incoming arrows
Apply the “rule of experience” to the items passing the “arrow test”
Once the ID is finalized, step 6 involves selecting and identifying the key items. This is done by finding the card or cards with the highest total number of arrows either coming out of or going into the card. Then find the card(s) with the next highest totals, etc. The team will review all the cards, looking for those that have predominantly outgoing or predominantly incoming arrows. If you have a card where the outgoing arrows are dominant, this indicates a basic cause which, if solved, will have a spillover effect on a large number of items. Likewise, items having a dominant number of incoming arrows represent an issue, or possible bottleneck or barrier. Be careful not to be stuck with the rule of arrows, but apply the rule of experience to the items passing the arrow test.

14. Predominantly Outgoing Arrows
Root Cause
Predominantly Outgoing Arrows
Root Cause
As shown here the factors with predominantly outgoing arrows can be identified as root causes of the problem in question.

15. Predominantly Incoming Arrows
Key Issue
Predominantly Incoming Arrows
Key Issue
Likewise, items having a dominant number of incoming arrows represent a key issue, or bottleneck, that may actually be as important to address as the original item. Remember, key issues are things you need to keep in mind as you do the project, even though they are not root causes to the underlying problem.

16. Construction Steps 7. Draw the Final ID
 Identify the key issues and root causes by double boxing e.g.
The last step is to identify the key issues or the root causes on the diagram by double boxing that particular item.

17. Interrelationship digraph
Optimize Protocol
Quantify inputs/outputs
Optimize inputs
Identify Physical differences
Identify variables only present in the robotic process
Optimize equipment
Here we see an example of an Interrelationship Digraph that shows how various factors affect each other and how by counting the number of incoming and outgoing arrows we can identify the key issues and root causes of the problem.
Optimize environment
Key Issues
Identify time differences
Identify environmental differences
Root Cause

18. Matrix Format What are the barriers to a great vacation? Root Cause1 2 3 4 5 6 7 8 9
Out In
Total
1. Lack of family consensus on location        6 1 7
2. Ineffective Travel Agent        5 2 7
3. Bad weather    3 3
4. We can’t relax  8
5. Too much to do      1 4 5
6. Expect too much from it      2 3 5
As I mentioned previously, the ID can also be displayed in a matrix format as shown here by the following example on the issue of: What are the barriers to a great vacation? In this particular case, factor #1, lack of family consensus on location is shown to have an influence or effect on factor #2, an ineffective travel agent. Thus and arrow is shown going from 1 into 2. Also, looking at the total number of arrows in and out, it is clear that factors #1 and #8 have the highest number of outgoing arrows, indicating that these two factors are possible root causes. Likewise, factor #4 has the greatest number of arrows going in, indicating that it is the key issue that needs to be addressed regarding this problem. Factor #9 is also a possible key issue.
7. Too little to do       2 4 6 7
8. No time for research into location 
9. Bored kids       1 5 6
Root Cause
Key Issues

19. Advantages
The key issues and root causes in problem solving become readily apparent
Explanation of complex issues to others is simplified
As further information is added, it is easy to update
The ID has many advantages. After one or more iterations, the key factors for solving the problem become apparent as the team identifies the root causes and key issues for the problem at hand. This helps explain complex issues in a manner that is simplified and easily understood. Also as further information is added, the ID is easy to update and share with others.

20. Always use a noun and a verb to succinctly define the factor
Disadvantages
Despite appearances, constructing an adequate diagram is surprisingly difficult
If the diagram is too complicated, it becomes difficult to understand and important factors might be overlooked
If the factors are expressed too simply, the arrows may point in many misleading directions.
Despite its power and relatively simple appearance, constructing an adequate ID can be difficult. For example, the ID may be difficult to understand if there are a large number of factors. Thus the ID may appear to be too complicated, and consequently important factors might be overlooked. Ideally, I try to keep the number of factors analyzed in an ID to 15 or less if possible. Likewise, if the factors are expressed too simply, the arrows may point in many misleading directions. For example, poor communication might tend to appear to connect to everything. Again, it is important that the cards be written with a noun and a verb, as we did with the affinity diagram to help overcome this potential disadvantage. In spite of its disadvantages, however, the interrelationship digraph is one of the more powerful tools available to management in the planning stage of basic problem solving where it is necessary to get a clear focus on the key issues and root causes of the problem before attempting to develop and implement solutions. It’s a great tool.
Always use a noun and a verb to succinctly define the factor

21. Thank You
This is the end of Interrelationship Digraph module. Thank you!