Chapter 2
Defining the Problem Steps and
Decision-Making Skills
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Today’s Menu
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Defining a problem statement
Surveying
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Existing Designs
Customer Needs
Writing a literature survey of existing
designs is important
Understanding the needs of the
customer is essential
Actually writing a “good” problem
statement is a skill that requires and
precise and questioning mind
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Today’s Menu - continued
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Identifying functional requirements
using an Objective Tree
Recognizing constraints and
limitations
Using Sketches to illuminate idea
Iterative definition of the problem
Defining a team and a schedule
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2.1 Forming the Problem
Statement
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A problem statement is a written
description of the problem to be
solved
Has open-ended >1 solution
 Is loosely structured and bound by
constraints
 Is part of a systems’ context
 Is usually accompanied by
sketches
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Figure 2.1 (Page 28)
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2.1.1 Research and Data Gathering
 Information gathering is
conducted via traditional sources
and reliable web pages
 It forms the basis of a literature
survey
 Conducting surveys among
potential users provides a better
understanding of the market
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Figure 2.2 (Page 31)
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Figure 2.3 (Page 32)
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2.1.2 Eliminating Biases and
Overcoming Assumptions
 No biases means having a systematic
exploration of the whole space of
feasible designs
Example
Designing a mechanical arm that will pick apples
from a tree
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“Why does one need to pick apples off the tree?”
(They could be shaken off the tree instead.)
“Why do apple trees have to be the shape they are?”
(Perhaps the shape of the tree could be modified to make it
easier to remove apples.)
“Why does the arm have to go up and down with every apple it
(The apple could be dropped into a chute or container.)
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2.1.3 Analyzing Key Phrases
 Starting with statements biased by the
customer’s and designer’s perceptions
& preconceptions
 Redefining the problem might uncover
the real problem (e.g. tomato picker
example)
 Shatter habitual patterns of thought, by
defining problems in increasing detail
 Look for justifications in the problem
statement  hint at the real problem
 Understand the context in order to
arrive at precise problems definition
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2.2 Identifying Functional
Requirements
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Functional requirements are the “what” of a
design NOT the “how” to design

Go from start to end as fast as possible (on the
second run) with the cheapest robot (in terms of
components used)
NOT
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Build a robot that goes through a maze twice,
mapping the maze on the first run then making use
of that information to determine and traverse the
shortest route on the second run
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In Summary (1/2),
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A well-written problem statement is
the door to good solution
development
Part of defining the problem is:
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Reviewing existing designs
Understanding customer requirements
In the final analysis, a well-written
problem statement should define the
space of acceptable designs
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2.2.1 Using Objective Trees
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Successful problem definitions
involve breaking a problem into
smaller ones
This can be done by constructing
an objective tree
An objective tree grows through
iterative addition of more details
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Figure 2.5 (Page 37)
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2.3 Recognizing Constraints and
Limitations
The “what” and “how” of a design are
shaped in part by the “but” and
“however” of constraints and limits
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Figure 2.6 (Page 38)
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2.3.1 Using Sketches
 Drawing pictures of the problem can help
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you see the problem from a different
perspective
It can illuminate new constraints and
limitations that were not apparent before
2.3.2 Clarifying the Problem Over
Time
 New
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information is discovered throughout
the iterative design process
Discovering problems often leads to
corrections
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2.4 Defining a Schedule and
Forming a Team
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Long-term
planning
follows
problem identification
Team failure often leads to project
failure
True mutual dependency is a
success key for all the team
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Figure 2.8 (Page 41)
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In Summary (2/2),
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An objective trees is a tool for
refining functional requirements
Identifying and incorporating
constraints into the problem is
important
Visual aides always help
Once the problem is defined, a team
and an initial schedule can be
formed
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