This step is to logically extrapolate a conceptual model from each root definition, to show each operational activity which would be necessary to carry out the process described in the root definition.
1. Taking a root definition, think about each of the activities which would have to take place, in order that the system described functioned properly.
2. Express each of these functions as a single phrase using a single verb
3. Incorporate the activities into a conceptual model, showing where each activity is dependent on another.
4. Incorporate the 3 E's as defined in stage three.
Conceptual models are a way of expressing logically-derived ideas about what systems should be in place in an organisation, according to the root definitions. The models will be used in later stages as bases for discussing what is really happening, and for finding ways to deal with the problem situation.
Building a conceptual model involves constructing a diagram of a system which looks like this: (picture of a conceptual model)
Parts of the model
The large boundary is called the system boundary.
Each of the bubbles within the system boundary represents an activity.They are numbered, but the numbers do not need to be in any particular order (the first activity to take place need not be called number 1, except for convenience).
The arrows which join the bubbles represent dependency (i.e., an arrow from bubble 1 to bubble 3 shows that activity 1 must take place before activity 3 can take place).
Contents of the model
Each activity in a conceptual model must contain one (and only one) main verb that describes the activity.
Each model should contain approximately 7 plus or minus 2 activities.
All of the activities in any single conceptual model should be at the same level of definition. That is to say, you should not include an activity which could be considered to be a constituent part of another included activity. An activity which is a constituent part of another activity belongs in a model at another level (see below).
If an activity in any model seems particularly important, or needs expansion, then you can repeat the root definition and conceptual modelling process, using that activity as the main transformation.This new model will be one level of definition lower than your original model.
The model in context
You should find that the 'what' of the higher level model maps directly on to the 'why' of the lower-level model.
Remember to take in to account the 'what' and the 'why' from the root definition. With this in mind, ensure that your conceptual model does not simply show the 'how', but also represents a system that achieves the 'what', and will, in the long term, contribute to achieving the 'why'.
Note
Conceptual modelling is the part of the SSM process which new users of SSM often find the most difficult. Here are some pieces of advice:
- The limit on the number of activities of seven plus-or-minus-two is a strong guideline. It is not compulsory, but SSM users often find that seven plus or minus two helps them to include enough detail but also to maintain the same level of resolution.
- Think of the Activity model, the Root Definition and the CATWOE analysis as a triangle. There should be nothing in the activity model which cannot be derived logically from the Root Definition. The CATWOE should make sense in terms of the Root Definition, and the activity model should be consistent with the CATWOE. If any of these are not the case, then the user should look again at all three to work out what can be improved and where.
By the end of this stage, the practitioner should have built a set of models to represent her/his thinking about the situation, which are logically and defensibly derived from the Root definition, and which also make sense in terms of the CATWOE analysis.
This entirely logical set of models and analysis is now ready to be compared against the illogical, messy real world.