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What is a system? A collection of components organized to accomplish a specific function or set of functions. [IEEE STD ]

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Presentation on theme: "What is a system? A collection of components organized to accomplish a specific function or set of functions. [IEEE STD ]"— Presentation transcript:

1 CO6031 Systems Analysis for Health Informatics Week 5 Soft Systems Methodology

2 What is a system? A collection of components organized to accomplish a specific function or set of functions. [IEEE STD ]

3 Soft Systems - Background
General systems theory attempts to understand the nature of systems which are large and complex A system is a set of interrelated elements In an IS, the technological aspects are less complex than the human aspects Open & non-deterministic Human System Computer System Closed & predictable

4 SSM – Background (2) Many methodologies deal only with technological aspects Structured approaches typify this (e.g. SSADM & JSD) Philosophy: Systems exist and can be engineered But they produce solutions that are not ideal –the importance and complexity of human factors are underestimated “hard systems” and precision v. “Soft systems” and fuzziness 1981 Peter Checkland – developed SSM through “action research"

5 Why adopt a Soft Systems Approach?
When problems are not clear When there are several points of view to identify a “recognised” problem When there is a general sense for the need to improve but no one knows what or how

6 Aristotelian philosophy
A Holistic approach to systems- The whole is greater than the sum of the parts The properties of the whole are not explicable entirely in terms of the properties of its constituent elements difficult data process easy

7 Underlying assumptions of hard & soft systems approaches
Hard Systems View Soft Systems View The activity of IS development is all about building a technical system made only of software & hardware An IS also comprises the social context in which the technical system (s/w & h/w) will be used Human Factors are chiefly important from the perspective of the software’s usability & acceptability. Politics & group behaviour are only an issue for project managers A new IS impacts on interpersonal communication, social organisation, working practices & much more, so human & social factors are paramount Organisations exist only to meet rational objectives, through the rational principles of business management. It is possible to be both rational & objective about the requirements for a new system Organisations are made up of individuals with distinct views & motivations, so any picture of requirements is subjective. It is not always possible even to reach a consensus. In practice this means the powerful decide, not the wise. When requirements are uncertain or unclear, it is up to management to decide. Setting objectives is a principal role of management & others should follow their lead If management has not accommodated the full range of views in the organisation, it may be completely counter-productive to encourage managers to decide requirements (After Bennett et al, 2002)

8 “Hard” versus “Soft” problems
Flat tyre Political hostages v. What & how? How to reach the goal? Purpose and “mission”? Hard & soft approaches can complement each other…

9 The Flynn Contingency Framework
(after Bennett at al 2002) Requirements Uncertainty High Low Linear model (hard) Integrated model (soft & hard) Evolutionary & prototyping approach (hard) Soft systems approach (soft) Process Uncertainty High Low

10 Soft Systems approaches
We should always be looking at “the system” in terms of the wider system of which it is a part E.g travelling to Mexico Before you go Booking accommodation / transport – communications systems Flight time Connecting flights? Air Traffic Control + getting to and from Airports Traffic systems + Getting through check-in and arrivals More booking systems Security systems Luggage systems + eating & drinking & sleeping ….

11 SSM stages 1 – The problem situation - analysis 2 – ‘Rich pictures’
3 – Root definition CATWOE 4 – Conceptual model 5 – Compare model with reality 6 – Propose changes to system 7 - Take Action

12 (reproduced from Avison & Fitgerald 1995)
The real world The systems world

13 The Soft Systems Approach Techniques – Rich Pictures
SSM uses “rich pictures” – cartoon-like diagrams -to build up a “picture” of the system to help in the construction of a “root definition”. This “rich picture” is to represent: Communication flows Processes Areas of conflict External observers Interactions

14 Rich Pictures – an example
Patching’s rich picture of a PUB as a problem situation Patching, D. (1990). Practical Soft Systems Analysis

15 The Soft Systems Approach Techniques – Root Definition
Root definitions are concise verbal descriptions of systems, to capture their essential nature. They are used to define two very vague concepts: Problems and Systems A root definition is well-informed when it answers “who is doing what for whom, and to whom they are answerable, what assumptions are being made, and in what environment is this happening?” The root definition should be derived from the information gained from within the organisation; i.e. the root definition should be a description of what the organisation believes itself to be doing

16 The Soft Systems Approach Techniques – CATWOE
Customer(s) – victims or beneficiaries of T Actors who would perform the T Transformation processes – the conversion of input to output Weltanschauung – viewpoint which makes the root definition (this T) meaningful in concept Owner(s) – those who can stop T Environmental constraints- elements outside the system which it takes as given

17 Root definition template (Liz Guy, University of Aberdeen)
A [O] owned system which under the following environmental constraints which it takes as given [E] transforms this input [i] into this output [o] by means of the following activities [T], the transformation being carried out by these actors [A] and directly affecting the beneficiaries or victims [C]. The worldview which makes this transformation [T] meaningful contains at least the following elements among others [W]. A root definition per system may be needed for each Actor or Weltanschauung…

18 Root Definition – example Customer root definition of a pub:
A system owned by the publican, and operated by the employees, visiting entertainers and customers of the public house, that identifies and satisfies the needs of customers for affordable drinks and entertainment, in an environment that influences customers’ socialising and drinking preferences, constrained by legal requirements and local opinion affecting the provision of pub facilities. (see Patching, D (1990) – Practical Soft Systems Analysis)

19 Further Reading http://www.bola.biz/research/ssm.html
Checkland P (1981), Systems Thinking Systems Practice, Wiley Checkland P & Scholes M, (2001), Soft Systems Methodology in Action, Wiley Bennett S et al (2002), OO Systems Analysis & Design. McGraw Hill (ch.22) Avison & Fitzgerald (1995), IS Development: Methodologies, Techniques & Tools (ch.6)


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