As Class Convenes

1
As Class Convenes

• Find your team
• Get the team folder
• Remove any returned work
• Sign the attendance sheet

2
Learning Objectives

• Achieve awareness of the difficulties in creating
  Metrics
• Achieve awareness of expectations concerning
  specifications and final concept

3
Session Agenda

• Quiz on Reading 5 min
• Creation of Metrics 20 min
• FunctionalDecomposition 5 min
• Specifications Modeling 45 min

4
Metrics Are

• Quantifiable measures used to determine if the
  Needs are met (or how well the Needs are met)
• Dependent variables (e.g., the weight)

5
Metrics Are Not

• Physical descriptions of the Concept (i.e.,
  things that show what the Concept looks like)
• Design variables or parameters (e.g., length,
  width, height, tensile strength)

6
Creating Metrics

• Context development of a Water Pistol
• Needs shoots far, hard, straight easy to
  shoot doesnt hurt hand fast easy to refill
  holds lots of water not too heavy or big
• Task generate Needs-Metrics Matrix

7
Possible Needs-Metrics Matrix
8
Two Questions About Specifications

• What are Specifications?
• specifications are the values of the metrics that
  define what is acceptable, i.e., feasibility
• How do you show your concept meets specs, i.e. is
  feasible?
• you must predict values for each specification

9
Modeling Metrics Specifications

• Let
• mj be the jth metric
• di be the ith design variable
• sk be the kth specification
• Then a typical design problem is find dis such
  that
• mj(d1, d2, d3, , , di) lt sk

10
Concept - Specification Task

• For the distance shot and force required metrics
  of the Water Pistol
• develop models that allow you to predict the
  metrics value
• highlight the design variables used in your models

11
Functional Decomposition