Principles of Information Systems Session 07 Problem Identification and Solving

Principles of Information SystemsSession 07

Problem Identification and Solving

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Problem Identification and Solving

Chapter 6

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Overview

Learning objectives

1. What is a problem?

2. Structure and complexity in problems

3. Puzzles, problems and messes

4. General methods for solving problems

5. From problems to solutions

6. Creative problem solving strategies

7. Summary

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Learning objectives

• Identify different kinds of problems and approaches to their solution

• Distinguish problems, symptoms and problem situations

• Explain the difference between puzzles, problems and messes

• Apply the various problem-solving methods in appropriate solutions

• Recognize wicked, intractable and insoluble problems

• Describe some techniques for creative problem solving

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What is a problem?

• Examples for people,

organisations, society

Problem or symptom?

- Irritant or sign e.g. Ibises in suburbs –nuisance or sign of drought

• Problem analysis - an important skill

1. What is a problem?2. Structure and complexity3. Puzzles, problems and messes4. General methods 5. From problems to solutions6. Creative problem solving strategies7. Summary

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Identifying the real problem

• Distinguishing symptoms from deeper problems- tingling hands may seem a trivial problem but may be a symptom of a stroke or diabetes

-high staff turnover may lead to extra recruitment and training costs. Underlying problem may be low morale and people are leaving because of bad managers

• Problem analysis aims at finding deeper problems that underlie or cause an apparent problem.

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Problem situations

• Can be a set (or system) of related problems

• Losing your job• Can’t pay for house• Partner leaves you• Stress from all this …

• Which do you fix first?

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Problems

Givens : what you have at the start

Operations : what you can do with what you have

Goals : what you are trying to achieve

I’m Winston Wolf, I solve problems.Jimmie: Good, ‘cause we got one.

(Wayne Wickelgren)

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• Given: and • Operation: Insert a vowel• Goal: Make a complete English word

• Given:• Operations: arithmetic • Goal: Combine to make 20

Examples

3 42

S _ C K

A E I O U

+ / x-

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Example: Bagh Chalhttp://en.wikipedia.org/wiki/Bagh_Chal

Example

Given: an incomplete chessboard and 31 dominosOperation: place dominos on boardGoal: until board is covered

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Problem analysis

• Wickelgren’s idea applies widely: puzzles … organisational strategy … warfare…

• Analysis involves: identifying components and regularities

whether there is enough information

• Some problems are intractable:

(not easily controlled or directed; not docile or manageable; stubborn; obstinate.)

• They need other types of approach for a solution

Problems worthy of attackProve their worth by hitting back

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Problems can range from simple puzzles to

complex and messy situations.

Problem analysis and problem

identification are important skills.

All problems have

givens, operations and goals

Recap

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Structure and complexity• Amount of formal structure

- the more structure a problem has, the easier is a generalised solution.

• Amount of complexity - more complex problems are less tractable


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Structure - examples

• Abdul is older than Bob • Bob is older than Christine

-age is structured (transitive)

Equivalently• Abdul is taller than Bob• Bob is taller than Christine

• “who is tallest” has same structure

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Problem: Where does John live?

John, Val and Diarmuid all live in the Perth area

• Val lives northeast of John• Meeting at Diarmuid’s house is most convenient

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Degrees of structure

• Structured problems: routine, readily solved with known methods. Suited to computer analysis.

• Semi-structured problems: part of the problem is structured. This part may be solved in a familiar way, then can support judgement

• Unstructured problems: no ready method of solution, may need to be structured somehow for solving or management.

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Examples

• Structured problem – sudoku

• Semi-structured problem- Choosing which car to buy within your budget

• Unstructured problem – should we build a dam?

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Complexity

• How many things are involved?

• How do they interact?

• Do they get messier over time?

• Are they combined with other problems in the wider situation?

• Problem structuring can help reduce complexity.

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Three levels of complexity

• Puzzles: well-defined whose fixed solution is readily worked out. (e.g Sudoku, FreeCell).

• Problems: well defined, but different exclusive solutions are possible. (e.g choosing a home computer, designing your garden)

• Messes: complex issues, not well defined, or without agreed problem definition. (e.g. dams, bypasses). Solutions must address the whole mess: ignoring relationships to other parts of the mess will lead to failure. (Ackoff)

Dragon Curve by Solkoll with extract

Structure and Complexity are similar

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Structure and complexity help define

problems.

The more structure a problem has, the

easier is a generalised solution.

More complex problems are less

tractable.

Recap

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Puzzles, problems & messes

1. Puzzles

2. ProblemsConstraint problems

Optimisation, maximisation and minimisation problems

Search space and NP-completeness

3. Messes

1. What is a problem?2. Structure and complexity3. Puzzles, problems and

messes4. General methods 5. From problems to solutions6. Creative problem solving

strategies7. Summary

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1. Puzzles

• Simple problems, commonly quantifiable or logical, with well understood methods

-What discount applies for cash now, rather than over a three-year term?

-How much feed to maintain yield from a stock of cattle? How many animals should I graze on this land to maximise productivity?

• Discipline-specific methods/formulae apply. -F = C/5 * 9 + 32 given 100°C – what is Fahrenheit?

• Solution usually unambiguous: exact numbers.

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2. Problems

• Some quantification, but also unknowns. (semi-structured).

-How many prisons/hospitals should we have?

-What export price to allow for tariffs and legal compliance costs in unpredictable market?

-How much should I spend on marketing, compared with research and development?

Possible approach: • Identify assumptions, work out a numerical answer, then

consider wider feasibility.

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How many hospitals? • Work out the population to be served by the hospitals,

the average percentage in hospital at any one time, and their average stay.

• Other information shows that: 1. The population is expanding

2. people are living longer

3. health problems increasingly manageable at home

4. a policy trend towards keeping people out of hospital where possible.

• Assumptions moderate original number up or down. Answers more approximate than exact.

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A general class: Constraint- satisfaction problems

• Set limits on what solutions are possible• May be quantifiable or qualitative in nature.

e.g. Decision problems with two alternatives or many-Where to place the next O-Where should my family live? -How should I vote?

• Some have no right answer, or many equally good or bad answers.

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Where should my family live?

Answers are needed! Often satisfactory answers are found by constraining the problem. House locations may be narrowed down by asking:

-Can I get to my place of livelihood from there?

-Can the children get to a good school?

-Is it in an attractive area

- Is transport convenient?

-Can I afford it?

-Does the whole family like it?

-Is it near the CBD?

-Can I get broadband? …

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Hard vs soft constraints

Such considerations constrain, but don’t determine the solution.

• Hard constraints are not negotiable - I must be able to get to my work place-F = C/5 * 9 + 32

• Soft allow some tolerance- proximity to the beach is debatable or can be relaxed (i.e. loosened or dropped).

• Typical solution may not meet all constraints but it may meet enough of them well enough. Not perfect but satisfies the requirements.

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Optimisation, maximisation and minimisation problems

Examples:-How to maximise shareholder value? -How to minimise staff turnover? -Optimal mix of products we should manufacture? -Optimal density of planting for best yield?-Stacking shipping containers at ports.

• Stacking containers is an optimisation problem. Find a balance between putting through as many containers as possible to maximise profit, and minimising the throughput time to remain competitive.

• Tools e.g. MS Solver

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Search space problems

• When many components interact this creates a very large set of possibilities. Perhaps only one combination is of interest.

-Sudoku -Travelling sales rep problem.-Which way should the travelling sales rep go?

• Computational complexity: - Brute force search may take forever, need more intelligent solution strategies.

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3. Messes• Puzzles and problems can be tamed. They apply in

idealised worlds, without social and political realities. But consider:

• Should this country have the death penalty? • How should we deal with poverty?• How can we fix the university parking crisis?

• Messes need managing not solving- deal with the situation vs solve the problem

• Problem and possible solutions (may) be defined, but method to reach solution is arguable. Some messes are wicked problems.

How can we fix the parking crisis?

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Puzzles, problems and messes

are three classes of problems.

Each has particular qualities and

general approaches to solution

which can be used.

Recap

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General methods for solving problems

• Pólya’s 4-step general method

1. Understand the problem 2. Devise a plan

3. Implement the plan 4. Reflect on the outcome

• Within each steps are prompts:- have you seen this before? - Solve a simpler problem.

• Pólya called these heuristics. They help you guess at or partly solve a more complex problem.


Heuristic: Solve a simpler problem

Sliding tiles puzzle

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Herbert Simon’s model

Closely related to “scientific method” but tailored to management decision problems

1. Intelligence: collect information, identify the problem2. Design: conceive alternatives, select criteria3. Choice: evaluate alternatives, select4. Implementation: put decision into effect, allocate

resources, control

Basis for other methods and versions

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There are some general

approaches that can be applied

to all problems,

e.g. Pólya's method and Simon’s

model

Recap

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From problems to solutions

Generally all aim at

(1) understanding and defining the problem

(2) designing a solution addressing a specifically defined problem.

5.1 Facets of problem definition

5.2 Approaches to problem solution- Puzzles- Problems- Messes and wicked problems


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problem definition

• Formulating problems: how a problem is described and represented makes it easier or harder to handle. Try these:

19+27+46+54+73+81= (1)19+81+54+46+73+27= (2)

7x6x5x4x3x2x1 = (3)1x2x3x4x5x6x7 = (4)

• These pairs have equivalent intellectual difficulty but (2) and (4) are easier.

A problem well stated is half solved

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Problem Ownership

• Who has the parking problem? - Students /staff who can’t park?- University officers?- Bus company?- Government?

- Solutions can cause problems!-A rail link may affect nearby houses-Multi-storey stops library expansion…

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Practice example: (from Gause & Weinberg)

A road tunnel through the Swiss Alps has been built. For safety a sign is made:

At a scenic viewpoint just beyond the far end of the tunnel people stop for photos and refreshment. Many then find their car batteries dead from leaving lights on! National police are fed up jump-starting cars. Tourists are upset.

WHOSE PROBLEM IS IT?

Tunnel ahead - please turn on headlights

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WHOSE PROBLEM IS IT?

• Drivers• Tunnel engineer• Gendarmes• Swiss canton president• Other• All of the above• None of the above

Probably the tunnel engineer’s problem

WHAT SOLUTIONS MIGHT WORK?

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Possible solutions

1. Sign at tunnel end?

2. Ignore it?

3. Battery chargers at rest stop?

4. Franchise battery charging?

Each solution causes new problems!

Turn off your lights

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Possible solutions

Sign at tunnel end?Problem: people should not turn off lights at night

Ignore it?Problem: no changes and loss of reputation

Battery chargers at rest stop?Problem: expensive, maintenance, unpopular…

Franchise battery charging?Problem: commercialises rest stop, unacceptable to tourists,

govt. …

A better sign?


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A better sign?

If it is daylight and if your lights are on then turn off your lights

If it is dark and if your lights are off then turn on your lights

If it is daylight and if your lights are off then leave your lights off

If it is dark and if your lights are on then leave your lights on


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Choosing which problem to solve

• Which problem to solve in a problem situation?-analysing specific problem components -prioritising and scoping

Medical triage at an accident. Who to treat first with the limited resources of ambulance officers and time?

An organisation identifies problems in its marketing, finance, IT, and innovation departments. Business analysis suggests fixing the IT aspects is most critical.

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Agreed conceptual models

• With (19+81)+(54+46)+(73+27)=all information is given, operations and goal are obvious

- Problem is understood so the solution is straightforward.

- The conceptual model is base 10 arithmetic

• Not always so clear e.g. in ethical questions.

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Accountancy puzzle

A trading company has this information for June:a. sales revenues = $ 150 000b. product costs of goods sold = $ 80 000c. purchasing costs = $ 5 000d. overhead costs = $ 30 000 1. Compute the gross margin in June;2. Compute the operating income in June.

-Arithmetic is straightforward, but conceptual model may be disputed. Different ways to calculate Product costs (w.r.t selling price, or yearly income statement)

-Different interpretation different result.

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Approaches to problem solution

• Puzzles have structure that may be used in defining more complex problems.

• e.g.Sudoku is a constraint satisfaction problem:

-Simple rules

-Universally played

-Develops thinking skills

-Only logic required

-Kids stuff

-Unique solution

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• Real problems also need insight into the world

-How much wine should I provide for a party?-At what rate should I repay my home loan?

• These (numerical) everyday life problems differ from maths puzzles, and use heuristics

-Allow one glass/hour over four hours each, and assume one case produces 60 glasses

(Pólya)-Guess likely answer and check - Work backwards-Draw a figure - Solve a related problem

Problems

http://www.wpclipart.com/food/beverages/alcohol/wine_glass.png

SEND +MORE MONEY

DONALD+GERALD ROBERT

Crypt-arithmetic and Freecell

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Practice problem

A rock climber sets off at first light to ascend a cliff-face. Taking all day, pausing at various tricky bits, he spends the night at the top. He starts climbing down at the same time the next morning. How can we prove that there must be a point on the cliff that will be passed at the same time of day, no matter how much more quickly he descends?

a diagram may be the best representation

step

x

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Messes

• Soft Systems Methodology (SSM)

• Strategic Options Development and Analysis (SODA)

• Strategic Choice Analysis (SCA)

• Morphological analysis

• The Viable Systems Model (see chapter 8)

• Scenario analysis

• Simulation of situations using system dynamics

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Soft Systems Methodology (SSM)

• Originated by Peter Checkland (1981)- ‘Systems Thinking, Systems Practice’

• Focuses on the human activity aspects and social and political contexts of a problem

• Provides guidance in defining complex problems thoroughly and identifying feasible and desirable solutions

• Rich pictures (chapter 3) are used widely in SSM

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Strategic Options Development and Analysis (SODA)• Developed by Colin Eden and Fran Ackerman• A version of cognitive mapping directly designed to

address organisational problems• An unstructured situation is organised into a structure

that surfaces understanding- Identifies relevant issues which are then clustered and linked

-Issues can then be dealt with in agreed action plans

-A shared map is produced

• A SODA map represents how problem owners and team members think through their decision making in messy situations

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Strategic Choice Analysis (SCA)

• John Friend and Alan Hickling

• Group planning decisions

• Targets situations where there are complex interconnections, lack of structure and uncertainty

• Recognises different sources of knowledge contribution, and forces a practicable level of consensus and learning

• Has been used in developing countries and by humanitarian organisations in disaster relief

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Morphological analysis

• Fritz Zwicky

• Deals with structure in messes

• Recognises that judgemental processes are involved

• Identifies the ‘shape’ of the problem space and how the parts interact

-Emphasises coherence and consistency, rather than quantification and causality

• Has been used in many organisations to invent and innovate

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Once a problem has been understood

and defined, appropriate methods of

solution come into play.

Puzzles, problems and messes have

different approaches to problem

solving.

Recap

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Creative problem solving strategies

• Avoid dealing head-on with the problem!- Reframe it- Examine its assumptions- Solve another problem- Refer it to someone else- Ask around- Procrastinate appropriately- Go around blockages- Sleep on it

1. What is a problem?2. Structure and complexity3. Puzzles, problems and messes4. General methods 5. From problems to solutions6. Creative problem solving

strategies7. Summary

The old nine dots puzzle

1. Without lifting your pen

from the paper, draw four straight lines that cross through all the dots.

2. If that is too easy, try this. Draw one straight line through all nine dots. ?

Over-constraining orlimiting the problem

J. Adams

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Conceptual Blockbusting (Adams)

Perceptual blocks Seeing what you expect to see

Emotional blocks

Fear of taking a risk Cultural and environmental blocks

Tradition is better than changeReason is good, intuition is bad

Intellectual blocks

using the wrong language (e.g. verbal vs. visual)

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Exercise (optional)

Table tennis ball inside a steel pipe buried in concreteSix of you have:

30m clothesline hammerChisel box of cerealFile wire coat hangerMonkey wrench light bulb

Think of ways to get ball out of pipe. (5 mins) (Adams, p54)

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Lateral Thinking (Edward de Bono)

• Digging a hole deeper is useless if it’s in the wrong place

-So reframe the problem

• At a tennis tournament, there are 131 players in the men’s singles. How many matches were required to decide the winner?“

• A truck is stuck under a bridge. How to get it out?

What is this?

?

What is this?

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Oblique Strategies (Eno, Schmidt)

• Turn it upside down

• Make an exhaustive list of everything you might do & do the last thing on the list

• Disconnect from desire

• Don’t be afraid of things because they're easy to do

• Is there something missing

• Do nothing for as long as possible

• Tidy up

• Do the words need changing?

…

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Malouff’s problem understanding strategies

1. Clarify the problem

2. Identify key elements of the problem

3. Visualize the problem or a relevant process or situation

4. Draw a picture of the problem or relevant process

5. Create a model of the problem or a relevant process

6. Imagine being the problem, a key process, or the solution

7. Simulate or act out a key problem element

8. Consider a specific example

9. Consider extreme case

10. Change perspective

11. Consider levels and systems

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Creating problem solving

strategies aim at freeing the

‘blocks’ to a solution,

e.g. by side-stepping, reframing,

or examining their assumptions

Recap

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Summary• “Problems” are very common

• All problems have givens, operations and goals

• Puzzles/problems/messes can be classified by degree of structure and complexity

• General approaches to problem identification and problem solving exist.

• There are some systematic types of solution:

-breaking problems down, using heuristics, reframing or creatively managing.

• Messes require more advanced techniques

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Documents

Principles of Information Systems Session 07 Problem Identification and Solving