Problem Definition


einstein.gif (22315 bytes)The mere formulation of a problem is far more often essential than its solution, which may be merely a matter of mathematical or experimental skill. To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science.



 

The First Four Steps

1. Collect and analyze information and data

2. Talk with people familiar with the problem

3. If at all possible, view the problem first hand

4. Confirm all findings

Step 1. Collect and analyze information and data

Don't jump to conclusion - Start with a open mind - Look at the big picture

bulletLearn as much as you can
bulletDetermine what information is missing and what information is extraneous
bulletThe information should be properly organized, analyzed, and presented
bulletCommunicate using drawings, sketches, and graphs
bulletDisplay numerical or quantitative data graphically


Problem Definition Techniques



The Case of the Dead Fish - Consider the case of a chemical plant that discharges waste into a stream that flows into a relatively wide river. Biologists monitored the river as an ecosystem and reported the following data of the number of dead fish in the river and the river level:



Graphs of the type shown above are called time plots and control charts.

The acceptable level of dead fish was exceeded on August 1 and 15.

We discover that on July 29 there was a large amount of chemical waste discharged into the river. Discharges of this size had not caused any problems in the past.

There has been little rain and the water level in the river was low on August 1

Step 2. Talk with people familiar with the problem

bulletLooking past the obvious
bulletChallenging the basic premise
bulletAsking for clarification when you do not understand something
bulletAsk insightful questions


Seeking Advice

Here is a problem encountered by a major hotel a number of years ago: this hotel had become very popular, the elevators were very busy, and frequently caused backups in the lobby area.

Adding additional elevator shafts would require removal of a number of rooms and a significant loss of income.

The doorman, overhearing their conversation, casually mentioned that it was too bad they couldn't just add an elevator on the outside of the building

A great idea!

It occurred to the doorman because he was outside the building much of the time, and that was his frame of reference.

Step 3. If at all possible, view the problem first hand


You can see a lot by looking - Yogi Berra

bulletYou should not rely on other people's interpretations of the situation or problem
bulletGo inspect the problem yourself


In the mid 1970s a company completed a plant to produce a plastic product (PVC). The main piece of equipment was a large reactor with a cooling jacket through which water passed to keep the reactor cool.

When the plant was started up, the plastic was dark, nonuniform, and way off design specifications.

The engineers in charge reviewed their design and refined their model and calculations. However, the problem did not change

Finally after many days, one of the engineers decided to look into the reactor. He found that a valve had been carelessly switched to the wrong position.

Step 4. Confirm all findings

bulletCross check and cross reference data, facts, and figures
bulletChallenge assumptions and assertions

Boxright had installed a new process for recovering and recycling their "cooking" chemicals used in the paper making process.

After two years, the process had yet to operate correctly.

Courtland Construction was the supplier of the recycling equipment.

Courtland presented data and information from an article in the engineering literature that they claimed proved Boxright was not operating the process correctly.

When Boxright analyzed this information in detail, it was stated that the data would not be expected to apply to industrial-size equipment or processes.

Problem Definition Techniques



Find out where the problem statement came from


Never
assume the problem statement is correct

bulletWhere did the problem originate?
bulletWho posed the problem statement in the first place?
bulletCan that person explain the reasoning as to how they arrived at that particular problem statement?
bulletAre the reasoning and assumptions valid?
bulletHas that person considered the situation from a number of different viewpoints?
bulletHave you used the first four steps to gather information about the problem?


The Case of the Dead Fish

 


The Situation: "Design a new waste treatment plant to reduce the toxic waste from the chemical plant"

bullet

Who Posed the Problem?
(company upper management's)

bullet

Can reasons for arriving at the problem statement be explained?
(company wants to deflect negative press)

bullet

Are the assumptions valid?
(company has decided to treat the symptoms)

bullet

Has sufficient data been collected?
(our engineer initiates his own investigation)

Exploring the Problem

 

  1. Identify All Available Information

  2. Recall or Learn Pertinent Theories and Fundamentals

  3. Collect Missing Information

  4. Solve a Simplified Version of the Problem to Obtain a "Ballpark" Answer

  5. Hypothesize and Visualize What Could Be Wrong with the Current Situation

  6. Brainstorm to Guess the Answer

  7. Recall Past or Related Problems and Experiences

  8. Describe or Sketch the Solution in a Qualitative Manner or Sketch Out a Pathway That Will Lead to the Solution

  9. Collect More Data and Information

  10. After Using Some or All of the Activities Above, Write a Concise Statement Defining the Real Problem


The Case of the Dead Fish

 

Our engineer initiates his own investigation

bulletIdentify Available Information - toxic discharge, river level low, large number of dead fish
bulletLearn Fundamentals - call biologist about what could kill fish
bulletMissing Information - a fungus in nearby lakes could kill fish, temperature was quite high, fish dead up and down the river
bulletHypothesis - Fish dying because of fungus not discharge
bulletMore Information - an examination of the fish concluded that they did die of a fungus not the discharge
bulletDefine the Problem - Identify ways to cure infected fish and prevent healthy fish from being infected


Present State/Desired State

 

"You can't get there from here"

bulletPresent State/Desired State - help us verbalize where we are and where we want to go.
bulletPresent State statement should match the Desired State statement
bulletThe Desired State should not contain solutions to problems that are not in the Present State


Hitting 'Em Where They Aren't


The Situation: "During WWII, a number of aircraft were shot down over Germany. Many of the planes that made it back safely to base were riddled with bullet and projectile holes."

Instructions: "Reinforce these damaged areas with thicker armor plating"

Present State Desired State
Many bullets penetrating aircraft Fewer planes shot down
Many bullets penetrating aircraft Fewer bullet holes
Many bullets penetrating aircraft Fewer bullets penetrating in critical and noncritical areas critical areas

 

 

The Duncker Diagram

 

bulletThe Duncker Diagram points out ways to solve the problem by making it OK not to reach the desired state.
bulletThere are two General Solutions:
  1. Solutions that move from the present state to the desired state
  2. Solutions that modify the desired state until it conforms to the present state
bulletFunctions Solutions are possible paths to the desired state
bulletSpecific Solutions implement the functional solutions


bulletFunctional Solutions - What to do.
bulletSpecific Solutions - How to do it.


Kindergarten Cop



bulletThe real problem was how to lower her stress at her workplace


To Market, To Market



bulletThe real problem is the cereal was not staying fresh long enough

Statement-Restatement

"A problem well-stated is a problem half solved"

bulletSimilar to Present State/Desired State
bulletRestating the problem is important to inject ideas



Problem Statement Triggers

  1. Vary the stress pattern-try placing emphasis on different words and phrases.

  2. Choose a term that has an explicit definition and substitute the explicit definition in each place that the term appears.

  3. Make an opposite statement, change positives to negatives, and vice versa.

  4. Change "every" to "some," "always" to "sometimes," "sometimes" to "never," and vice versa.

  5. Replace "persuasive words" in the problem statement such as "obviously," "clearly," and "certainly" with the argument it is supposed to be replacing.

  6. Express words in the form of an equation or picture, and vice versa.


To Market, To Market

Trigger 1

bulletCereal not getting to market fast enough to maintain freshness.
(Do other products we have get there faster?)
bulletCereal not getting to market fast enough to maintain freshness.
(Can we make the distance/time shorter?)
bulletCereal not getting to market fast enough to maintain freshness.
(Can we distribute from a centralized location?)
bulletCereal not getting to market fast enough to maintain freshness.
(How can we keep cereal fresher, longer?)

Trigger 2

bulletBreakfast food that comes in a box is not getting to the place where it is sold fast enough to keep it from getting stale.
(Makes us think about the box and staleness... what changes might we make to the box to prevent staleness?)

Trigger 3

bulletHow can we find a way to get the cereal to market so slowly that it will never be fresh? (Makes us think about how long we have to maintain freshness and what controls it?)

Trigger 4

bulletCereal is not getting to market fast enough to always maintain freshness.
(This change opens new avenues of thought. Why isn't our cereal always fresh?)

Trigger 5

bulletThe problem statement implies that we obviously want to get the cereal to market faster to maintain freshness.

Thus, if we could speed up delivery freshness would be maintained. Maybe not! Maybe the store holds it too long. Maybe it's stale before it gets to the store.
(This trigger helps us challenge implicit assumptions made in the problem statement.)

Trigger 6

bulletFreshness is inversely proportional to the time since the cereal was baked.



Makes us think of other ways to attack the freshness problem. For example, what does the proportionality constant, k, depend upon?

Evaluating the Problem Definition

bulletHave all the pieces of the problem been identified?
bulletHave all the constraints been identified?
bulletWhat is missing from the problem definition?
bulletWhat is extraneous to the problem definition?
bulletHave you challenged the assumptions and information you were given to formulate the problem?
bulletHave you distinguished fact from opinion?

If you break the problem apart...   be sure to put it back together

 

The Next Four Step

bullet

The First Four Steps of Experienced Problem Solvers

  1. Collect and analyze information and data.

  2. Talk with people familiar with the problem.

  3. If at all possible, view the problem firsthand.

  4. Confirm all findings.

bullet

The Next Four Steps

  1. Determine if the problem should be solved.

  2. Continue to gather information and search the literature.

  3. Form simple hypotheses and quickly test them.

  4. Brainstorm potential causes and solution alternatives.

 

Step 5. Determine if the problem should be solved

bulletDevelop criteria by which to judge the solution to the real solution
bulletWhat are the resources available to solve problem?
bulletHow soon do you need a answer?
bulletThe quality of your solution is often related to the time and money you have to generate it and carry it through.



Which Technique to Choose

A survey of over 400 problem solvers showed that the choices were divided equally among those presented in this section

This web site was originally developed by Charles Camp for his CIVL 1101 class. This site is maintained by the Department of Civil Engineering at the University of Memphis. Your comments and questions are more than welcome.