ENGR 100 Lecture 12: Engr 100 - Lecture 12
Engr 100
Intro to Engineering
Spring 2019
Parento Principal (aka the 80/20 rule)
● 80% of the cost and quality of a product are determined by the decisions made in the first
20% of the product development process
● In other worlds, it is much more expensive to recover from errors early in the design
process. So the most important design decisions are the early ones.
Lecture #8: Problem Definition: Clarifying the Objectives (Chapter 4)
● Clarifying client’s objectives by the Objective Tree (Section 4.1)
● Rank-ordering objectives by Pairwise Comparison Chart (Section 4.3)
● Measuring the achievement of objectives by Metrics (Section 4.2 and 4.4)
Clarifying Client’s Objectives by Objective Tree (Section 4.1)
● Typically, we start with a list of objectives (see table 4.1 for example; this list can be
extracted off the Lists of Design Attributes, see Table 3.1 for example); we then can
organize or group the objectives so that – there are some hierarchies
● Objective Tree is a graphically representation of the hierarchy of design objectives, see
Figure 4.1 and 4.2
Rank Ordering Objectives by Pairwise Comparison Chart (PCC) (Section 4.3)
→ Objectives are not equally important; or they are not of the same value to the client or
user(s)
→ PCC is a means to measure the objective’s relative value
→ PCC is applied to objectives under the same grouping and at the same level
Individual PCC for a Ladder Design
→ Between objectives A and B
o 0.5 if A and B are equally important
o 1 for A, 0 for B if A is more important
o 0 for A, 1 for B if B is more important
A Few Notes Regarding using PCC
→ Objectives are compared only at the same level under the same grouping
→ Higher objectives should be compared/ ranked before those at the lower level
→ PCC is subjective
→ Ranking is relative, a zero score does not imply that the objective in question is not
important
Document Summary
80% of the cost and quality of a product are determined by the decisions made in the first. In other worlds, it is much more expensive to recover from errors early in the design process. So the most important design decisions are the early ones. Lecture #8: problem definition: clarifying the objectives (chapter 4) Clarifying client"s objectives by the objective tree (section 4. 1) Rank-ordering objectives by pairwise comparison chart (section 4. 3) Measuring the achievement of objectives by metrics (section 4. 2 and 4. 4) Clarifying client"s objectives by objective tree (section 4. 1) Objective tree is a graphically representation of the hierarchy of design objectives, see. Rank ordering objectives by pairwise comparison chart (pcc) (section 4. 3) Objectives are not equally important; or they are not of the same value to the client or user(s) Pcc is a means to measure the objective"s relative value. Pcc is applied to objectives under the same grouping and at the same level.
