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UFCE8V-20-3 Information Systems Development 3 (SHAPE HK). Lecture 17 Soft Systems Thinking. Human Activity Systems (HAS). All human activity systems (HAS) are social systems. All social systems are open systems. They consist of people and their activities.
Lecture 17Soft Systems Thinking
Five classes of system which make up a systems map of the universe.
– investigate, describe, learn from, natural systems
– create and use designed systems
– seek to ‘engineer’ human activity systems (P Checkland)
Specifically developed to be used in messy or ill-structured situations. That is, situations where there may not be a clear view of what constitutes the problem, or for that matter, what action should be taken to overcome the difficulties being expressed.
Examples of soft systems methodologies include -
Four underlying principles. Learning, culture, participation and the “two modes of thought”.
The problem situation can be expressed as a “rich picture”. The idea is to represent pictorially all the relevant information and relationships. This is simply to aid the modeller or consultant to gain an understanding of the situation. The rich picture will reveal one or more Human Activity Systems (HAS).
“Root definitions” are constructed for the relevant HAS identified in stages one and two. The root definition should encompass the emergent properties of the system in question. To define the emergent properties one needs to consider the mnemonic CATWOE:
Each root definition will result in a conceptual model.
The conceptual model identifies the minimum necessary activities for that Human Activity System(HAS).
In addition, it represents the relationships between the activities.
The conceptual model must be derived from the root definition alone. It is an intellectual model and must not be clouded by knowledge of the “real” world.
All of the elements of the CATWOE mnemonic must be included somewhere in the conceptual model, otherwise the conceptual model is incomplete. It should not be possible to take out words from the root definition without affecting the conceptual model.
[** Note that ‘conceptual models’ here are very different to conceptual (ER) models]
Stages five and sixThe conceptual model identifies which activities need to be included in that particular HAS. It is not concerned with how these activities will be carried out. The conceptual model will be compared with the real world to highlight possible changes in the real world. It may be that activities in the conceptual model do not exist in the real world. This would then be a recommendation for change. Differences between the two must never result in a change to the conceptual model. The conceptual model, if constructed correctly, encompasses all the activities necessary for the emergent properties of the system. Removal of activities from the conceptual model would result in those emergent properties being lost. Conversely, it may be the case that activities appear in the real world that do not fit into the conceptual model. These activities are either unnecessary, or are included in the conceptual model in a different form.
Stage sevenRecommendations for change will be implemented. It is important to appreciate that once these changes have been implemented, the problem situation will be modified. In other words, the process is cyclical.
“A householder-owned and manned system to paint a garden fence, by conventional hand painting, in keeping with the overall decoration scheme of the property, in order to enhance the visual appearance of the property & the lifetime of the fence”