How to do an Influence Diagram

An Influence diagram shows, in any given situation, the main structural features and the important influences that exist among them. Why is this important?

If you are kickstarting a new project and haven't assessed who might influence the outcome of the project, what are you likely to achieve? It may well work out perfectly, but if you haven't taken major influencing factors into account, your risk of failure is far higher. 

Furthermore, as our brains work better with pictures and we retain the information better, analysing at the beginning using pictures how the project or project components may be influenced will stand to you when you have to make decisions and especially in spur-of-the-moment or spontaneous decisions. 

An Influence diagram is one quick way to get an overview to an activity, a process or organization and the main relationships. This way you can make better decisions on what to do, because of the very fact you can see who is influencing who and how activities you may organise could play out. 

This diagram or analysis tool can be used to either explore the interrelationships that could lead to refocusing a group, the laying down of new priorities or even re-definition of a system that you have organised. (See Systems if you are not sure what I mean by that)

What you need to do an Influence Diagram

Influence Diagram

You use:

  • “Blobs”
  • Assorted arrows; the size of which will indicate the size and strength of the influence, and
  • Words; these label the blobs and possibly the arrows.

Influence Diagram Example


  • You can show system boundaries by using a perimeter line that encompasses a particular grouping of items, activities, persons or groups.
  • You can use arrows to join up components or show the strength of influence one exerts over another – or even more than one other.

Note 1:

Remember that the arrows serve to show the influence or relationship status and should not serve to show the flow of materials or the sequence of process flows. In other words, the arrows show the capacity to influence, not a sequence in time or events.

After all, this diagram will be just a snapshot in time.

Note 2:

Please avoid using arrows from elements in the environment directly to the system boundary. They should always end up at a specific system component (a person or a group, indeed an organisation) or at an activity within the system. This is because, it goes without saying, that elements of the environment will always influence your system, so these arrows to the system boundary are superfluous.

Note 3:

Avoid using double-sided arrows as this implies equal influence exerted by both elements and this is seldom the case. Use two single direction arrows (as with arrows 6 in the Diagram). Always add a clear legend, giving any reader the ability to accurately interpret what you are trying to convey.

Making your System Robust

A successfully carried out Influence Analysis will highlight risk factors relating to powerful relationships or weak positions. 

You also will have gathered new insights as to the role played by external influences on the area you are assessing.

Your decision making will be better - also how you communicate what is going on. If you have the major influencer "on your site" / "backing your case", you will have half the battle won. Think about not knowing who your influencers are - and not realising that one great influencer is against progress towards your objectives. How differently would the outcome be then?

By addressing the weaknesses and gaining from the strengths, you will make your concept more robust. In a way, you are assessing the risk in the situation you are evaluating and enabling yourself to design counter-measures to minimize the risks.

Try out an this diagram as part of your Problem Solving Approach or as part of Change Management. 

It is a simple but extremely effective tool to have in your work skills box! 

› Influence Diagram