1. this lecture is about problem formulation,
lecture 2 : the problem situation
this lecture is about problem formulation,
We discuss:
the components of a problem situation
mind maps
rich pictures
boundary setting
Spring ÇG
IE398 - lecture 2

2. Spring ÇG
IE398 - lecture 2

3. components of a problem
decision maker
objectives
decision criterion
performance measure
control inputs or courses of action
problem context or situation
this is just a rough sketch; in practice the situation is more complicated and formulation has to go through progressively more refined reformulations and refinements as deeper insight is gained: this pocess is called problem structuring or issue structuring
Spring ÇG
IE398 - lecture 2

4. goal indicates overall purpose
objective this is sometimes more specific than a goal
e.g. finding the best location for an ambulance service
(note however that the Daellenbach&McNickle text makes no distinction between a goal and an objective)
performance measure: an o/p that serves to measure system performance
objective function: mathematical expression of performance measure, expressing o/p as a function of control i/p’s. e.g. profit to be maximised or distance to be minimised
decision criterion: e.g. maximise expected profit , maximise rate of return on investments; minimise total distance, minimise the longest distance etc.
Spring ÇG
IE398 - lecture 2

5. problem customers, the affected
stakeholders (roles assumed with respect to the narrow system of interest):
problem owners
problem users
problem customers, the affected
analysts (e.g. the OR analyst or the IE)
Spring ÇG
IE398 - lecture 2

6. role definition is important; e. g
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 wider system of interest
if doctors or women’s groups initiate the project, concern will be about minimising incidence and fatalities, and 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
Spring ÇG
IE398 - lecture 2

7. 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
Spring ÇG
IE398 - lecture 2

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IE398 - lecture 2

9. Spring ÇG
IE398 - lecture 2

10. 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
Spring ÇG
IE398 - lecture 2

11. a system model specifies:
the transformation processes or activities of the system
the boundary, ie. the narrow and the wider systems of interest
subsystems of the narrow system involved in transformation; the dynamic relationships ie. processes; stable relationships ie. structure
uncontrollable inputs; control inputs; decisions and decision rules
outputs that are desired, undesired, planned, unplanned
outputs serving as performance measures
Spring ÇG
IE398 - lecture 2

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IE398 - lecture 2

13. Spring ÇG
IE398 - lecture 2

14. remember how Ackoff describes the systems approach:
three steps in the systems approach:
1. identify a containing whole (system) of which the thing to be explained is a part.
2. explain the behavior or properties of the containing whole.
3. then explain the behavior or properties of the thing to be explained in terms of its role(s) or function(s) within its containing whole.’
from “Our changing concept of the world”, R. Ackoff
Spring ÇG
IE398 - lecture 2

15. boundary setting the narrow system of interest and its environment
level of detail
issues, conflicts to/not to address
essential for ST
inputs, outputs, controls
stakeholders and their impacts
performance measures
Spring ÇG
IE398 - lecture 2

16. Endless expansionism in inquiring about the ‘whole’?
“we have come to believe that complete understanding of anything, let alone everything, is an ideal that can be approached continuously but can never be attained. Therefore, there is no need to assume the existence of an ultimate whole which if understood would yield the ultimate answer.”
Spring ÇG
IE398 - lecture 2