lecture 2 : the problem situation
we discuss:
• the components of a problem situation
• mind maps
• rich pictures
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components of a problem
• issues and problems that are the subject of inquiry
occur within a context that we call the “problem
situation”
(the context is that part of a system's
environment that can neither be influenced nor
controlled)
• involved in each problem situation, are
–decision makers
– objectives
– decision criterion
– performance measure
– control inputs or courses of action
• we can make these more clear as follows
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• goal indicates overall purpose
e.g. setting up an ambulance service
• objective is more specific than a goal
e.g. finding the best location for an ambulance service
(the textbook makes no distinction between a goal and an objective)
• decision criterion: a rule by which we judge the
achievement of an objective
e.g. maximising expected profits or the rate of return on
investments; minimising total distance travelled, or the
longest distance travelled etc.
• performance measure: an output that serves to
measure system performance
• objective function: mathematical expression of
performance measure, expressing o/p as a function of
control i/p’s, (decision variables)
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• stakeholders (roles assumed with respect to
the narrow system of interest):
– problem owners who have control over some
aspects of the problem situation, such as
choosing a course of action
– problem users who use the “solution”, ie.
implement the decisions of problem owners
– problem customers, the affected
beneficiaries or victims of the solution to be
implemented
– analysts (e.g. the OR analyst or the IE)
address the problem and develop a solution
that must be approved by peroblem owners
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• role definition is important; e.g. consider the
case of screening for breast cancer:
– if the Health Minister initiates the project, concern
will be about effective allocation of funds,
priorities, trade-offs, costs; the entire health system
will be the of interest
– if doctors or women’s groups initiate the project,
concern will be about minimising incidence of
cancer and fatalities, not directly over costs
– users may need to be persuaded and trained lest
they sabotage implementation
– roles may need to be reassigned for efficiency or
efficacy
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mind maps and rich pictures
these are useful as a first step in setting down and
representing our perception of the problem situation
where:
•all aspects of a problem situation are mapped on a
free-style diagram with or without pictures
•including as much or as little detail as necessary
•independently of any particular W (ie. world view)
but as a joint product of conflicting views of the
situation
•without trying to identify any systems as yet
•redrawn as many times as needed in the course of
the project
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these diagrams should show:
• elements of structure; stable or slow-changing
aspects such as buildings, equipment, products,
rules, advantages, difficulties etc.
• elements of process; dynamic aspects that
change fast such as activities, material flows,
information etc.
• relationships between structure and process and
consequences of these relationships
• soft as well as hard facts
• multiple aspects to facilitate learning and
discussion
• not too many connectors, precedences or flows
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