SoftSystemsMethodology(Lecture2)
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Transcript of SoftSystemsMethodology(Lecture2)
Lecture 2Lecture 2Lecture 2Lecture 2
Root Definition and Conceptual Model
Systems Analysis and Design (UCM0558E)
Abdisalam Issa-Salwe
Thames Valley University Faculty of Professional Studies
2
Overview of SSM Stages
situationconsideredproblematic
problemsituation
expressed
real world
systems thinkingabout real world
conceptual modelsof systems describedin root definitions 4
comparison ofmodels andreal world 5
6 changes:systemically desirable,
culturally feasible
7 action toimprove the
problem situation
3root definition
of relevant systems
2
1
Source: Checkland: Systems Thinking, Systems Practice
3
Two relevant models
� Root Definitions are used to identify what the system's purpose is, who the interested parties are
� Conceptual Models are used to say how the system would function, i.e. what activities are necessary for it to take place.
4
Defining systems
� The variety of influences in a human activity system to be collected in a rich picture
� ordering takes place within the area of systems thinking rather than real world investigation.
� The situation is examined by defining systems (inputs-transformations-outputs) which are relevant to it and working out the activities that will be necessary for such a system to function.
5
Formal systems model (and examples)
6
Stage 3: Root Definition (RD)
� The root definition is one way of describing� what is the system� how the system will work, and � why we need this system.
� It is expressed as a transformation process � some entity as input a new form of the entity as output.
Note: We should not confuse the how here with the how of implementation,� the how in the root definitions gives a general framework of
how we are going to do this but it is not how that defines certain technology and certain steps to be taken.
7
Notional description
� Root definitions as notional descriptions of the purposes of systems: � they look at an organisation or situation from different points
of view. � It is perfectly possible for there to be several views of the
same situation. � Take the following definition of the work of which produces
graduates in vocational subjects to satisfy the needs of industry and commerce:The university is a system in which academic departments are
responsive to the needs of industry and has its performance judged by industry and the funding council. The assumptions
are that it is possible and necessary to define the requirementsof industry for qualified graduates in particular subjects.
8
Two types of RD
� Primary Task Root Definition:
� concern processes which the organization being studied performs as a part of their regular activities (for example, in an oil company, the process of refinement of the oil).
� Issue based Root Definition:
� Issue Based Root Definitions concern processes which are rare or one-off occurrences (such as a management restructuring).
9
Root definition examples
A university owned and operated system to implement a quality service (X), by devising and operating procedures
to delight its customers and control its suppliers (Y), in order to improve its educational products (Z).
issue based (relating to temporary or qualitative concerns, or concerns of judgment)
A university owned and operated system to award degrees and diplomas to suitably qualified candidates (X), by means of suitable
assessment (Y), (in conformance with national standards), in order to demonstrate the capabilities of candidates to potential employers (Z).
primary task (relating to basic tasks and structures)
10
Root definitions syntax
a system to do X by (means of) Y in order to Z
they follow the form:
� short textual statements which define the important elements of the relevant system being modelled - rather like mission statements
what the system does - Xhow it does it - Y
why it’s being done - Z
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CATWOE
CATWOE analysis helps to build coherent and comprehensive root definitions
� Each conceptual system has at its heart a transformation process in which something, an input, is changed, or transformed, into some new form of itself, an output.
� Accompanying this transformation ('T' for short) is a weltanschauung, or worldview –� Weltanschauung defines the belief or point of view
that makes the transformation reasonable - worth achieving.
� Together, T and W form the core of CATWOE analysis -a mnemonic which helps to build coherent and comprehensive root definitions.
12
CATWOE stands for
Customers the victims or beneficiaries of TActors those who do TTransformation input outputWeltanschauung the worldview that makes the T
meaningful in contextOwners those with the power to stop TEnvironmental elements outside the system which constraints are taken as given, but nevertheless
affect its behaviour
T = Transformation
13
Some procedures for deriving root definitions of relevant systems
� Identify a problem which seems important enough for further investigation
� Structured root definition has three parts, referred to as what, how and why.
� the 'what' is the immediate aim of the system, � the 'how' is the means of achieving that aim, and � the 'why' is the longer term aim of the purposeful
activity � We can compose root definitions by naming a series of relevant
systems using the formula:“ A system to……..by……………in order to…………….”
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CATWOE
� to formulate and structure the real world situation in a meaningful way and also to ensure that the RD written does really represent the relevant system
� both the root definition and the CATWOE analysis is to consider each of them with respect to the other one, if there is any kind of inconsistency then this is a clue that there is something seriously wrong in the SSM practitioner understanding of the problem situation and he has to go back and iterate to stages one and two
15
Deriving relevant systems
� relevant systems are conceptual (in-the-mind) models of parts of the problem that are of interest
� they are models which follow systems principles to help structure the analyst’s impression of the problem - not definitive descriptions of systems in the real world
� problems can be represented as they are perceived by different stakeholders
16
C candidate studentsA university staffT candidate students
degree holders and diplomatesW the belief that awarding degrees and
diplomas is a good way of demonstrating the qualities of candidates to potential employers
O the University governing body
E national educational and assessment standards
CATWOE example
17
Starting point:
best starting point is to think first of the output of the transformation, the thing that the system is there to do, working out the transformation from that and then moving on to the Weltanschauung, such as:
Who (A) is doing what (T) for whom (C), having someone to whom they are answerable (O) and
working within certain assumptions (W) and within wider constraints in the environment (E).
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Stage 4: Conceptual Model
� CM as the core of the SSM methodology:�To establish a relevant system based on
defining the minimum number of activities required for this relevant system to be the one described in the root definition.
� It is a human activity models that is used to show each operational activity that is necessary to carry out the process described in the root definition. There must be at least one conceptual model for each RD.
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Basic component of CM
20
activity models - symbols
verb + noun phrase
A
B
activity - ‘do something’
logical dependency arrow - activity A must come before B, or if activity A is done badly - so will B
study MSc
take MScexamination
cook dinner
eatdinner
boundary
21
How to build CM
To build a conceptual model1. take the RD and think of the different activities
that must be implemented to fulfill this RD2. then express each activity in a phrase
containing one verb, and 3. finally associate these activities in a CM
showing dependencies of the activities and the flow of the information.
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activity model - example
enrol studentsdesign
educationprogrammes
appreciatenational
standards
educatestudents
allotresources
designand carry outassessment
awarddegrees + diplomasto students reaching
acceptable levels
A university owned and operated system to award degrees and diplomas to suitably qualified candidates (X), by means of
suitable assessment (Y), (in conformance with national standards), in order to demonstrate the capabilities of
candidates to potential employers (Z).
23
Measurement of performance
Measurement needed to incorporate with performance for this conceptual model.
� Formal System Thinking � Monitoring the System
24
Formal Systems Thinking
� applied to the development of the conceptual model. � serves as a guideline for checking the conceptual model.� Example, S is a formal system if and only if it meets the following
criteria:� S must have some mission � S must have a measure of performance � S must have a decision making process � S must have components which interact with each other such that
the effects and actions are transmitted throughout the system � S must be part of a wider system with which it interacts � S must be bounded from the wider system, based on the area
where its decision making process has power to enforce an action
25
Monitoring the System Monitoring the operational system consists of
three activities:1. Define a measure of performance:
� Efficacy - does it work� Efficiency - How much of work completed given
consumed resources� Effectiveness - Are goals being met.� Note: Many including ethical, elegant, economical and other metrics
which may be dependent on the context of the work being done
2. Monitor the activities in the operational system, in accordance with the metrics defined in step 1.
3. Take control action: Use the outcomes of these metrics to determine and execute action to control the operational system.
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Example of Monitoring of performance
� E1 (efficacy) - are degrees and diplomas awarded?� E2 (efficiency) - how many degrees and diplomas, of
what standard, are awarded for the resource consumed?
� E3 (effectiveness) - do employers find the degrees and diplomas a useful way of assessing the qualities of potential employees?
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The complete model - example
enroll studentsdesign
educationprogrammes
appreciatenational
standards
educatestudents
allotresources
designand carry outassessment
awarddegrees + diplomasto students reaching
acceptable levels
monitor forE1, E2, E3
take controlaction
� E1 (efficacy) - are degrees and diplomas awarded?
� E2 (efficiency) - how many degrees and diplomas, of what standard, are awarded for the resource consumed?
� E3 (effectiveness) - do employers find the degrees and diplomas a useful way of assessing the qualities of potential employees?
C candidate students
A university staff
T candidate students
degree holders and diplomates
W the belief that awarding degrees and diplomas is a good way of demonstratingthe qualities of candidates to potential employers
O the University governing body
E national educational and assessment
standards
A university owned and operated system to awarddegrees and diplomas to suitably qualified candidates (X),by means of suitable assessment (Y), (in conformance with
national standards), in order to demonstrate thecapabilities of candidates to potential employers (Z).
28
More example of building a CM
"A system to meet a perceived requirement for web-based resources intended to help users teach and learn SSM methodologies by constructing and publishing appropriate web pages in order to help interested parties to teach and learn". The suggested activities are:
1. Identify potential users for learning resources2. Know about capabilities of world wide web medium3. Know about authoring and publishing web pages4. Know about methodologies and how to teach them5. Identify likely help needed by potential users6. Identify ways of meeting users' teaching/learning needs7. Design web pages intended to meet users' likely needs8. Construct web pages9. Publish web pages
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Activity dependencies and explanations for the conceptual example
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The complete conceptual model
� Root definition� CATWOE� Activity model� Measures of performance
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The conceptual model for a web-based system
32
Stage 5: Comparison
� Deals with the comparison between the conceptual model(s) developed in stage 4, and the structured analysis of the problem situation from stage 2 .
� Purpose is to analyse the similarities and differences between the model and the real world in a thorough and structured manner. � Note: the analyst will likely find out where the
models are unrealistic, as well as determining where the new ideas generated from the modelling might be of practical use in the situation being examined.
33
Approaches to using comparison
� several approaches to use when comparing the real world with the models derived from the root definition. The most important are:� 1) using conceptual models as a base for ordered
questioning, � 2) comparing history with model prediction, � 3) general overall comparison, and � 4) model overlay.
34
Conceptual models as a base for ordered questioning
� can be done when the real world situation is very different from the conceptual model.
� approach can be used when the two models are different.
� technique is simply to generate questions about the existing system.
� questions should be written down and answered systematically. Questions should be generated for each activity in the conceptual model.
35
Comparing history with model prediction
� prediction involves reconstructing events that occurred in the past and asking what would have happened if the relevant conceptual model had been implemented at the time.
� this technique should be used diligently because it could reveal inadequacies.
36
A general overall comparison� This can be used with a comparison table. A
comparison table usually involves systematically going through each activity and link (i.e., a relationship between two activities) in the conceptual model(s) and asking specific questions about the differences
37
The technique of model overlay
� This involves directly overlapping the concept map derived from the root definitions with a second model that is used to represent what actually exists. � Although the second conceptual model has not yet
been created (there only exists a rich picture), the conceptual model derived from the root definition can be used to create the second conceptual model.
Note: be wary of forgetting or misusing elements during the construction of the real-world concept model because the systems thinking conceptual model may be quite different from the real world.
38
Comparison with the real world
activityis it done in the real situation?
how is it done?comments,
recommendations
1
2
3
39
A comparison table for estimates effort.
40
Example of a basic comparison of a conceptual model
41
42
Problems and problem owners
43
Stage 6 and 7:
Definition of Desirable and Feasible Changes
The purpose:� to define those changes that are most feasible and
desirable. � the possible changes from the previous stage are
considered and weighed using several criteria, including the cost and benefit of the change, and the political feasibility.
� those changes that seem likely, if implemented, to have a positive outcome in the situation are recommended.
44
Steps be followed
For each proposed change, the following should be described:
1) Reason for change: The reason for the change should include arguments for why the change was suggested in the first place;
2) Nature of change: an explanation of the context of the change.
3) Means to bring about change: means and steps required to bring about the change;
4) Potential long-term effects of change: The long-term implications of the change to the system should also be considered.
45
The impact of Change
� The political feasibility can be analysed by considering for whom the expected outcome will be positive. Must be considered:� who will likely oppose the change, and why. � to examine the relative power of the individuals for and
against the change.� Cost feasibility analysis includes the cost implications.
� For example, how much will the change likely cost, and do the benefits justify the costs.
� Benefits should include short and long-term benefits that might offset or justify the cost.Note: Stage 6 includes a general framework for how to approach the weighing of the potential changes.
46
Stage 7: Recommended Action
� Purpose:� to help the practitioners recommend the change. � also include the actual starting of the change process.
Note: � It is important to note that the introduction of the action may
change the situation so that new problems may arise.� It may be a good idea to carry out the change in a temporary
mock system to gauge the repercussions. � This method of testing would have to be on a fairly simple
system otherwise it could require a lot of resources. Once a temporary system is used and observed by an analyst, it could then be introduced into the real system.
47
Preferred option(s)
� First, select the preferred option(s) from the previous step. � the steps that are expected to have the greatest
positive effect. � There should be a clear understanding about whose
point of view the so-called positive effect is from. � It should also be understood how the opposition will
react to the changes, and how they should be dealt with. After these issues have been considered, the final findings can be presented to the client in the form of a report.
48
The Final Report
� The final report should include the following elements:
1) an outline of the measures recommended,2) the benefits of the change, 3) the costs of the change, 4) the cultural and political implications, and 5) the feasibility of the measures. Of course, the
conclusions should be easily understandable for all of the actors (i.e., stakeholders) within the organization.
49
References:
Shehata, Mohamed and Seth Bowen (2000), “Soft Systems Methodology”,http://sern.ucalgary.ca/~bowen/613/report/#figure8a
Dale Couprie, Alan Goodbrand, Bin Li, David Zhu (1997). Soft System Methodology. http://sern.ucalgary.ca/courses/seng/613/F97/grp4/ssmfinal.html
Checkland, P.(2000). System thinking, System practice. John Wiley & Sons, New York, NY.
Checkland, P. and Scholes, J. (1990). Soft Systems Methodology in Action. John Wiley & Sons, New York, NY.