lecture 8: soft OR, soft ST
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an example
characteristics of soft systems problems
terminology
a list of soft methodologies
Checkland’s SSM: “soft systems
methodology”
• other methodologies
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hard/soft distinction is not so clear and exact:
• soft aspects are almost always present in any
problem situation, and hard thinking can be
useful even in pluralistic or coercive situations
• the soft perspective should not be neglected
altogether when doing hard OR and vice-versa
• and, most importantly, problem situations that
look suited to hard OR at first sight, are often
more complex than they appear
• consider the BAKÜ-CEYHAN example [adapted
from “Tools for Thinking” by M Pidd, Wiley 2003]
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the “BAKÜ-CEYHAN” example:
• oil from Bakü is piped by BOTAS to tanks in Ceyhan where
it is then pumped into waiting tankers and shipped to
consumption points
• technology used involves flexible hoses about one metre in
diameter that connect the oil tanks, via pumping stations, to
the tankers in the harbour
• hoses are subject to twisting forces and this sometimes
causes failures in service; when this happens there is a
large spillage of crude oil until the pumps are switched to
auxiliary hose lines
• until recently, the hoses have been bought from ABC, a
supplier who was the original manufacturer of these hoses;
the same company has provided replacements as
necessary
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• over the last two years, two new suppliers – TUV and
XYZ - have appeared in the hose market both claiming
that their hoses are at least as good, though they can
undercut ABC prices by up to 40%
• the BOTAS Port Manager (PM) is very keen to reduce
his costs and has insisted that one of the pumping
stations is switched to XYZ Hose for a trial period
• there have been problems during this trial and the
BOTAS Pumping Officer (PO) is unhappy about what he
feels is a much higher rate of hose failure than was the
case with ABC products
• the PM, the PO, the BOTAS Maintenance Manager
(MM) and you (a BOTAS IE) discuss the situation and
the conversation goes something like this:
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– PM: ... Yes, I know that the hoses seem to fail more often, but look
at the price; we save 40% on the prices charged by ABC. I'm not
bothered about shorter service lives with that reduction.
– PO: Even if the life is only 50% of ABC Hose?
– PM: Come on! It's much higher than that.
– MM: Well, I'm not too sure about that. But I don't really know what
the failure rates are. I'm sure that we could improve things by better
maintenance.
– PM: But if we stop the pumping just for preventive maintenance
then it costs money. There will be penalty to pay to the tanker
owners for a start.
– MM: It's still cheaper than having a hose blow oil all over the
harbour when it fails. Then we still have to stop pumping, but we
also have to replace the hose section. Then we have to clean up
the harbour. We also have the Greens on our backs about pollution.
I'm sure that better maintenance is the answer.
– PM: But it all costs money. There must be some way to work out
what to do. Don’t you have any ideas in the IE Department?
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this problem situation appears to be suitable for a hard-OR approach:
controllable variables seem to be:
1. the type of hose selected - ABCHose, XYZHose or TUVHose
2. the maintenance policies applied to the hoses once they are in use
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uncontrollable variables:
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the expected life of the different types of hose - this may be expressed in terms
of a probability distribution
the likely purchase price of the hoses
the likely costs of spillages, should they occur - this may also be expressed in
terms of a probability distribution
the costs of the different maintenance policies
decision criterion:
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minimise Expected (total cost) =
∑ [ E ( purchase price ) + E ( maintenance costs ) + E (spillage costs ) ]
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data requirements:
– hose prices: there may be no "price list" for such expensive items and,
instead, the prices may be negotiated between BOTAS and the hose supplier;
thus it may be better to think of Expected ( prices )
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– expected maintenance costs: first, are there any proper
records of the cost of existing maintenance policies? If so, they
may be used to estimate the likely cost of applying similar
policies. The complications then begin. Is it reasonable to
assume that similar policies will be needed for any type of hose?
Probably not if we take seriously the views of the MM: "I'm sure
that we could improve things by better maintenance." This
means that the apparently simple decision model based on cost
minimization may depend on at least one other model that
attempts to show the costs of different maintenance policies
– expected spillage costs: this will have at least two
components. First, some estimate of the likely costs of a spillage
and the number of spillages likely to occur. That is, some
estimate of the life/failure distribution is needed for each of the
three hose types. A further complication is that the service lives
will depend on the maintenance policies, otherwise there is no
point in having a maintenance policy. Thus, some model
showing the link between maintenance and hose life will be
needed.
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• thus, an apparently simple situation involving a choice among
only three known alternatives can turn out to be more
complicated than it would seem at first sight
• this is much more than a simple minimisation problem since
lifetime distributions for all hoses are hard to estimate, as are
the effects of maintenance policies
• suitable data will most probably be not be available such as
hose prices and cost of maintenance etc.
• if reliable data will not be available it will not be possible to
compute the cost minimising solution and decide the best
hose type and the best maintenance policy that goes with it
• these difficulties will complicate the problem situation even
more; there will probably be a divergence from the unitary
purpose of cost minimisation because different stakeholders
will have different purposes:
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– the PM was identified as the problem owner but there are other
stakeholders:
– for the PO, continuous and safe flow of oil may be more important
than costs, so the most reliable hose would be the best
– for the MM, an opportunity to show how effective maintenance is,
could be the most important concern
– therefore if these two internal stakeholders are not consulted and
decisions are not taken jointly, any proposed solution is likely to fail
– there are also external stakeholders to consider:
• tanker operators expect fast and reliable service irrespective of
cost
• politicians can have their own views about hose suppliers, hose
failures and service quality
• environmentalist groups will put all emphasis on reliability of
pumping
• local residents..
• hose suppliers..
• etc.
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• conclusion:
– the problem was described as a problem of hose choice, but we
know little or nothing about the history of the issue; we do not
know why this group, led by the PM, has decided to search for a
possible new supplier of these expensive hoses; it could be
pressure from one of the external stakeholders; it might be
dissatisfaction with the existing ABC hose; it might be that other
pressures within BOTAS make it important that something is
seen to be done at Ceyhan;
– there are many such possibilities and the careful analyst cannot
afford to either ignore or accept them; they all form part of the
mess with which she has to work
– problems do not exist in a vacuum, they exist in people's minds
and relate to their experience of the world and to their
expectations
– a purely functional hard-OR approach no longer appears to be
sufficient in this problem situation
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soft systems thinking/soft OR
• Churchman in 1960, then Ackoff, Checkland and others, rather
than accepting the narrow rationality of economic thought,
recognized that human decision making is more complex and
varied and is also governed by other than economic values
• they discovered that the process of decision making greatly
affects whether or not a 'solution' is accepted
• they expanded the narrow quantitative optimization focus to
include ideas from other disciplines, primarily critical philosophy,
sociology, and organizational behaviour
• this mixing of boundaries between disciplines can be seen as
part of the awareness that problems do not respect discipline
boundaries, that a narrow economic focus alone is insufficient,
and that human striving for quality of life, happiness, aesthetics,
equality, and justice is equally valid and legitimate
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• the proponents of soft OR/soft systems approaches point
out that the majority of real-life problem situations in
business, industry, and government violate most of the
assumptions underlying hard OR
• furthermore, the human aspects inherent in the problem
situation and the intervention process used should not
be treated as separate unrelated issues
• soft systems approaches were designed to deal with
complex problem situations, which are messy, illstructured, ill-defined, and not independent of people
• in other words, where different stakeholders with
different world views have different, possibly
conflicting perceptions about the problem situation
and about the appropriate objectives
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characteristics of soft systems approaches:
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These are problem structuring methods (PSM), structuring the
issues in a problem situation, rather than narrowly focussed
problem solving.
Facilitating dialogue between the various stakeholders with the
aim of achieving a greater degree of shared perceptions of the
problem situation, rather than providing a decision aid to decision
makers.
Addressing “what" questions first, and “how" questions
afterwards, i.e.
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What is the nature of the issue?
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What are appropriate objectives, given the various world
views of the stakeholders?
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What is the appropriate definition of the system for the issue
considered?
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Which changes are systemically desirable and culturally
feasible?
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How are these changes best realised?
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4. Eliciting the resolution of the problem from the
stakeholders themselves, rather than from the
analyst.
5. Changing the role of the problem solver to one of
becoming a facilitator and resource person who
relies on the technical subject expertise of the
stakeholders.
• note that 'how' questions, i.e. which means are
the best for achieving the desired objectives,
must ultimately also be addressed by soft
systems approaches; but they are often almost
obvious, rather than being centre-stage as in
most hard OR projects.
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there are several soft systems methodologies devised since 1950’s:
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Gaming (The Rand Corporation)
Metagame analysis (US Arms Control and Disarmament Agency)
Strategic choice approach (J. Friend, A. Hickling)
Strategic assumption surfacing and testing (R.O. Mason, I.I. Mitroff)
Social systems design (C.W. Churchman)
Social systems sciences, also as Interactive Planning (R.L.Ackoff)
SSM (P. Checkland)
Strategic option development and analysis (C. Eden)
Hypergame analysis (P.G. Bennett)
Robustness analysis (J. Rosenhead)
Theory of constraints (E. Goldratt)
Critical systems heuristics (W. Ulrich)
Drama theory (P.G. Bennett. M. Bradley, J. Bryant, N. Howard)
Total systems intervention (R.L. Flood, M.C. Jackson)
Multimethodology (J. Brocklesby, J. Mingers)
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• Checkland's SSM, Churchman's social system
design, and Ulrich's critical systems heuristics, are
firmly based on philosophical foundations and
systems theory
• gaming, metagame and hypergame analysis, and
drama theory originate in the ideas of game theory,
without the formalism of game theory
• SODA and drama theory have psychological roots
• total systems intervention and multimethodology are
meta-methodologies that help analysts determine
which paradigm and method or combination of
methods is most suitable for a given problem
situation
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• several of these approaches were developed through
action research, often within a practical consulting
context
• “action research originated in the work of Kurt Lewin
who, in the late 1940s, recognised the problems inherent
in the study of complex social and psychological
processes by breaking them apart (reductionism) and
taking them into the laboratory; he advocated instead
testing theory in action, in the process of
implementation
• action research contributes both to the practical
concerns of people in an immediate problematic situation
and to the goals of social science [“Systems Approaches
to Management”, MC Jackson, Kluwer 2000]
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• they all have one thing in common, while hard OR
deals mainly with the 'content' of the problem, giving
only limited concern to 'process', soft approaches
put equal emphasis on both content and process
• at the very start of an intervention, process is used
for extracting content and the underlying value
systems
• the methods seek to attain a reasonably
comprehensive view of the issues within their wider
context, although they recognize that true
comprehensiveness is impossible, nor may it be
needed to get to a workable solution or resolution of
the problem
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• the main aim is to gain a shared understanding
and mutual appreciations about values,
interests, objectives, choices for action
• boundary choices are subjected to critical
assessment and evaluation
• they also recognise that a resolution of a
problem does not necessarily require a full
convergence (ie. consensus) of views, and that
a mutual appreciation of views (ie. an
accomodation) may be sufficient to bring about
an acceptable compromise and commitment for
common action
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• few users are familiar with more than one approach,
although this is changing with several universities
offering courses and intensive workshops
• the consultant also needs to have good skills in
interpersonal relations, in facilitating and negotiation
• none of the soft systems approaches explicitly
address the various issues of implementation
• active participation of many stakeholders in the
project will hopefully help implementation of the
commitment package or recommendations made,
since the stakeholders are more likely to own the
solution
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• however, owning the solution is only a
beginning; planning for the actual process of
change and monitoring implementation and the
performance of the new system need to be dealt
with
• the structure diagram for PSM is given in Figure
7-11
• in contrast to hard OR, this is not a sequence of
systems whose outputs become the input into
the next system
• system S is 'created' or defined within system M;
note again how boundary judgements affect all
aspects.
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