Mastering systems thinking in practice
Mastering systems thinking in practice

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Mastering systems thinking in practice

4 Multiple-cause diagrams

Figure 4 Format for a multiple cause diagram

Purpose

This type of diagram is used to explore why a given event happened or why a certain class of events tends to occur. It is not intended to predict behaviour, but may be used to develop a list of factors to bear in mind when considering comparable circumstances in the future. They are also useful for finding out why something went wrong or keeps recurring e.g. through a causal loop, so that steps can be taken to prevent its recurrence. They can be derived from an influence diagram or developed anew. Sequential multiple cause diagrams are similar to activity sequence diagrams. They also share similarities with systems dynamics diagrams that you may encounter in the wider literature.

Elements

System boundary (optional)

Phrases

Arrows, which may be labelled

Title.

Conventions

  1. Inclusion of a system boundary is optional but highly recommended.
  2. The phrases (e.g. aaa, bbb, ccc, ddd, etc.) relate to the state of ‘things’ (e.g. flat battery). But, as the diagram is developed, it is preferable to describe the relevant variables associated with those things (e.g. decreased charge level in battery). Phrases may also represent events (e.g. corrosion of terminal).
  3. Arrows do not necessarily mean causes. They may be read as meaning ‘contributes to’, ‘leads to’, ‘enables’ or similar terms (but not ‘means’).
  4. The diagram may be entirely sequential, or it may contain loops.
  5. A title defining the system of interest is essential.

Guidelines

  1. In constructing such a diagram you normally begin at the factor/event to be explained and work backwards. A diagram should include more than one such end factor only if contributory factors were related, and explaining both events is important.
  2. Because the arrows may represent different kinds of contribution/cause, it may be helpful to label them.
  3. It is not necessary to put blobs around phrases, although if it improves clarity you can. Boxes, with their ‘designed system’ implications, are best avoided.
  4. It helps in checking a draft to ensure that each individual relationship is clear. Insert any necessary intermediate variables/factors if not.
  5. This type of diagram does not distinguish between necessary and/or sufficient causes (for example, in Figure 4, Event aaa and Event bbb may both be necessary if Event ccc is to occur; or either may be sufficient to cause Event ccc). If the distinction is important for your purpose you will need to annotate your diagram to indicate this.
  6. It is not necessary to indicate a system boundary on a multiple-cause diagram, particularly if it has been developed from an influence diagram that already has one. Drawing such a diagram may well, however, develop your ideas about where to draw a boundary and so identify a system of interest.
  7. It is important to remember that this diagram type, while superficially resembling an influence diagram, is different in that it is to be read sequentially, rather than as a snapshot representation.

Now go back to Week 4.

Skip Your course resources
MSTP_1

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371