BASICS OF PROBLEM DEFINITION
Characteristics of Problems
-Engineers are problem solvers.
-Problems are problems only when we are aware of them.
Crisis ---> Solution
-Problems are often confused with solutions -- leads to advocacy and early commitment, ownership, actions to save face.
-Don't accept the original problem statement – a person may believe that a demon causes his leg to hurt – this is a symptom of the problem – perhaps it is actually a broken leg.
-Problems are problems because they have no easy answers – if they did, they would be already solved.
-Solutions often become problems -- i.e. the automobile.
-Problems and values change over time. What was a good solution once doesn't work any more.
-Problems are total; solutions, disciplines seldom are.
-A problem is a problem if you believe it to be one.
-Anticipate and broaden your view of the problem.
-What are the relevant factors??Usually very many
•Technical
•Social
•Economic
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Components of Problem Definition
Describe System:
-What is the function of the system?
-Size of things -- constraints? Dimensions, weight.
-Environment -- weather, temperature, moisture.
-Skills, ability.
-People -- what particular types?
-Systems -- higher and lower level system goals, interfaces
-Flows -- how do pieces fit together, what activities are there and how are they related?
-Components -- what are the parts and what is their purpose?
Goals:
-What are critical factors, characteristics of an ideal system?
-What is the goal of your design?
-How do you measure performance of the system?
-What is wrong with the current system? In relation to your goals?
-Economics -- costs, value, prices, cash flow
Environment:
-The Market -- who uses it, what are their characteristics?
-The Competition -- what systems currently exist? Good points? Bad points?
-"Need to Know" list -- what do you have to know to work on the problem?
-Weather -- cold, warm, rain, dry, humid
-People -- size, strength, skills, literacy, handicaps, sight, hearing.
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-Materials -- strength, transport, soils, sources, durability, workability.
-Emergencies -- fire, flood, wind, safety, security, crime.
-Procedures -- construction process, labor relations, management, payments, schedules, sequences.
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Higher Order System
| variables | Parameter |
PROBLEM 
System
System
Good Inputs
Bad
Relationships
Problem Environment
Outputs
| ia | |
| r | |
| e | |
| t | |
| i | |
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| C | d |
| o | |
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| G | |
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mp d
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Problem
Boundaries
Lower Order System
Constraints
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Problem Solving Methods
There are three basic methods to solve problems
1)The Good Idea Approach. You are somehow inspired and have a "good idea" which you attempt to develop and defend against all criticism. This approach often leads to failure since there is usually a closed mind to other ideas. Bad news is ignored until it is too late.
2)The Scientific Method. Begin by stating a theory or hypothesis. Collect data and analyze it to determine if the theory/hypothesis is true or false. Not really a relevant method for design problems since it involves the search for truth rather than the search for an answer.
3)The Systems Approach. Three separate activities: problem definition, development of alternatives, and evaluation.
Problem
Definition
Alternatives
Evaluation
Don't define problems as solutions; i.e. build a better mousetrap.
Don’t reject alternatives prematurely.
Don’t evaluate until problem and alternatives are clearly defined.
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| The Systems Approach – Expanded Version | ||||||||||||||||||||
| Project Planning | ||||||||||||||||||||
| Problem Definition | ||||||||||||||||||||
| Identify higher order | Function | Identify | ||||||||||||||||||
| constraint | ||||||||||||||||||||
| goals, functions, | ||||||||||||||||||||
| outputs and needs | ||||||||||||||||||||
| Develop a large | ||||||||||||||||||||
| Identify system level | list of alternatives | |||||||||||||||||||
| goals, functions, | ||||||||||||||||||||
| outputs and needs | ||||||||||||||||||||
| Develop feasible | ||||||||||||||||||||
| set of alternatives | ||||||||||||||||||||
| Develop measures | Model | Cost model | ||||||||||||||||||
| of effectiveness | (predict performance) | |||||||||||||||||||
| Determine | Determine | Develop cost of | ||||||||||||||||||
| effectiveness of | ||||||||||||||||||||
| importance of goals | each alternative | |||||||||||||||||||
| each alternative | ||||||||||||||||||||
Evaluation
Iterate
...
{Uncertainty
Contingencies
Interpretation Sensitivity
Omitted
etc.
| No | Action? | ||
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