Diagrams for understanding are best developed within the creativity phase, though sometimes you can go straight on to using a diagram more suitable to the connectivity phase.
Most diagrams for understanding begin at the centre of the sheet of paper and work outwards. Buzan's (1974) spray diagram is built up from an initial idea with its branches; these branches have their own branches and so on until you reach the detail at the end of each twig. This technique is particularly useful for analyzing printed information which may be very difficult to understand; set out in diagrammatic form, one can see how balanced or disjointed the information is.
However, spray diagrams rely on there being logical connections between the elements and relatively linear relationships between the core idea and the detail at the periphery. So they tend to be more useful when you want a relatively straightforward ‘understanding’ of a situation and not when you want to develop a more creative understanding.
When Peter Checkland began to analyze human activity systems, he and his colleagues developed a technique which he called the rich picture because it contains more than should be necessary to understand the situation. Rich pictures need a lot of space and you don't have to be an art expert - indeed, artistic flair can sometimes be a diversion from the goal of drawing useful rich pictures.
Rich pictures require you to make pictorial representations of each of the elements in a situation and annotate any interactions and relationships between the elements in the situation.
These are not normally linear and the precise nature of the relationships between certain elements may be unclear. Don't try to impose order on a rich picture; it is intended to assist in understanding a complex situation and trying to impose order denies the very complexity of the situation. For example, if you identify ‘problems’ in a rich picture, you will have prejudged the situation and thus also what might be ‘solutions’.
Having said that, a rich picture may suggest interactions and relationships of which you had been unaware and you may wish to ‘redraw’ the picture to highlight these interactions and relationships.
This is perfectly alright as long as you keep the original picture to remind you what it looked like and remember that ‘redrawing’ a rich picture is the equivalent of moving from the creativity to the connectivity phase and imposing your version of a more ordered reality on the complex situation.
Relationship diagrams offer one way of putting more order into your understanding of a situation. Each element of a situation is named in an oval and lines between ovals indicate that there are relationships between the particular elements - but no more than this.
Systems maps are another way of developing one's understanding of a situation. Systems maps are essentially ‘structure’ diagrams. Each element or sub-system is contained in a circle or oval and a line is drawn round a group of elements or sub-systems to show that the things outside the line are part of the environment while those inside the line are part of the system. There are NO lines connecting elements, sub-systems or systems in a systems map; it is purely a statement of the structure as you see it in your mind.
Influence diagrams are developed from systems maps and indicate where one element in the situation has some influence over another. Arrows indicate the direction of the influence and the lines between elements may be of different thickness, shading or color in order to distinguish strong and weak influence. Strictly speaking, influence should only be shown from elements at a higher or at the same level in the system; that is to say, subsystems cannot influence systems and sub-systems and systems cannot influence the environment - but some people do not follow this convention.
Where a clear pattern of cause and effect can be discerned in a situation, the causal loop and multiple cause diagrams may be useful in describing the interactions between different elements in a situation. By convention, multiple cause diagrams have the elements laid out, without ovals or any other sort of enclosure, in whatever way assists in clarifying the processes.
Elements are joined by arrows indicating where there is a causal relationship between the elements. Where there is cause and effect in both directions between two elements, separate arrows indicate this.
To gain further understanding of the connectivity in a situation, a multiple cause diagram can be converted into a sign graph by indicating whether the cause has a positive effect or a negative effect by adding the respective signs.
Not all multiple cause diagrams lend themselves to this treatment as you need much greater knowledge of the situation to be able to be sure about the causal chains in a situation and the effects they are likely to have. Sign graphs are particularly useful for establishing the variables and relationships needed for a quantitative mathematical model.
Process engineers have long used diagrams to describe processes. Among these are input-output (or ‘black box’) diagrams and flow diagrams, in which linked ‘inputs’ and ‘outputs’ are described. These are sometimes split into flow-block diagrams describing flows between components and flow-process diagrams describing flows between processes.
Others include decision sequence diagrams, in which ‘decisions’ lead to ‘actions’ which lead to new ‘decisions’, and algorithms (or flow charts) in which the type of decision and the impact of alternative outcomes to a decision are set out diagrammatically. These all tend to be more suited to situations where the connectivity is relatively clear. Algorithms or flow charts are also invaluable when trying to convert a mathematical model into the steps that can then be translated into computer software code.
As the detail of the connectivity revealed through a diagram increases, many diagrams can be used for diagnosis by comparing a diagram of what should be happening with what is happening. This approach has been developed in detail by Bignell and Fortune (1984) to analyze systems failures.
They argue that all satisfactory systems have functioning decision-making, operational and performance monitoring systems and that many failures can be explained by a failure in one of these aspects, even when the other elements of the system were working satisfactorily. Other failures can be explained by weaknesses in connectivity between the elements of a system leading to ‘systemic failures’ - that is, failures in which individual elements of the system functioned satisfactorily in isolation, but the ways in which they were connected or interacted together led to a failure of the system as a whole.
The first principle in planning is: be clear about your own direction and purpose - in other words, your values and why you are doing anything. You can use the technique of asking why? And then why? of the answer. And then why? of the answer to that.
Keep repeating this process until you get back to your underlying values to create an objectives tree or network to help you define the direction in which you wish to go and the steps necessary to get there.
In an objectives tree, the statements you might make about what you wish to do, how you might do it and why you are doing things are related to each other. Why people are doing things should come at the top of the tree and how they are doing them at the bottom. With several levels, many what? statements are also how? statements in relation to a higher what? statement.
With such multiple objectives an objectives tree or network can become quite complicated, but should provide a clearer idea about the important relationships between what you are doing and why.
Conceptual models can be used to analyze a human activity system both to identify potential weaknesses in the connectivity of the human activity system and to plan human activity systems so that there is adequate connectivity between the elements in the system.
The most immediate how? Statements in an objectives tree or network can probably be related to a group of people who can be viewed as a human activity system about whom you can draw systems maps and conceptual models. Diagrams can be used to share understanding, diagnoses and design and the stages in implementing new relationships may be helped by the use of flow-block and decision-sequence diagrams or algorithms (flow charts) to plan a process or a relatively stable sequence of activities. Systems maps may help to orient people to new relationships and ways of working and you can use a spray diagram to plan any report or documentation you may produce.
Commonly used diagrams for communication follow conventions that are widely understood, many diagrams used for connectivity as previously discussed also lend themselves to use in communicating ideas.
A diagram developed for communication:
• Is large, clear and well laid out;
• Has shading and/or color for emphasis;
• Has a title; and
• Has a key to the meaning of all the symbols used in the diagram.
Annotation, notes and/or narrative may be necessary but in general two simple diagrams are preferable to one complicated one.
The type of diagram you draw depends on the purpose for which you draw it; bear in mind few people ever get it ‘right’ first time. If you are using diagrams to aid understanding of written material (or vice versa) put the diagrams as close to the text to which they refer - don't hide them away in an appendix.