1. 1 As Class Convenes  Find your team  Get the team folder  Remove any returned work  Sign the attendance sheet

2. 2 Learning Objectives  Achieve awareness of the difficulties in creating Metrics  Achieve awareness of expectations concerning specifications and final concept

3. 3 Session Agenda  Quiz on Reading5 min Quiz  Creation of Metrics 20 min  Functional Decomposition5 min  Specifications & Modeling 45 min

4. 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. 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. 6 Creating Metrics  Context: development of a Water Pistol  Needs: shoots far, hard, & straight; easy to shoot; doesn’t hurt hand; fast & easy to refill; holds lots of water; not too heavy or big  Task: generate Needs-Metrics Matrix

7. 7 Possible Needs-Metrics Matrix

8. 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. 9 Modeling Metrics & Specifications  Let –m j be the j th metric –d i be the i th design variable –s k be the k th specification  Then a typical design problem is find d i ’s such that: m j (d 1, d 2, d 3,,, d i ) <= s k

10. 10 Concept - Specification Task For the distance shot and force required metrics of the Water Pistol –develop models that allow you to predict the metric’s value –highlight the design variables used in your models

11. 11 Functional Decomposition Black Box Loaded Water Pistol Water Stream Apply Force Loaded Water Pistol Water Stream Move Water