Engineering Design Process

Achieving Excellent Project

• To achieve success in executing engineering and design projects, it takes an understanding of the design process, strong technical design tools, and professional skills.

Success of Product: Yesterday Competing costToday Quality Tomorrow Design

Engineering

• Engineer: One versed in the design, construction, and use of machines

• Engineers use methodical application of scientific knowledge and technology– Math, science and Fundamental

technologies

Innovation + Methodical Application of Science

Effective Engineering/Design

Design Process

• Prescriptive process for problem identification and requirements selection– Formal, all aspects are clear, algorithmic– Good for defined problems and solutions

Design Process

• Descriptive overview of the design process– Less formal – Less emphasis on exact

sequencing

A typical design is somewhere between

Descriptive and Prescriptive Design Process

The World-Class Engineer. (Leonhard Center for the Advancement ofEngineering Education, The Pennsylvania State University)

Strong technical stills and

understanding of the design process

Analytical Hierarchy ProcessBuilding a Decision Matrix

Analytical Hierarchy Process

• Selection Criteria– Cost – Safety– Design – Brand name

• Possible Selections– Honda CRV ($21)– Hyundai Tucson ($18K)– Toyota RAV4 ($22K)

Car Selection

Analytical Hierarchy ProcessCar Selection

• Scaling for comparing selection criteria: – 1 = equal– 3 = Moderate – 5 = Strong – 7 = Very Strong – 9 = Extreme

• Comparison of the selection criteria

Cost is three times more important than

design

Analytical Hierarchy ProcessCar Selection

• Scaling for comparing selection criteria: – 1 = equal– 3 = Moderate – 5 = Strong – 7 = Very Strong – 9 = Extreme

• Comparison of the selection criteria Power(21,1/4)

2.1/5.7=0.37

Car Selection - Cost Criteria

• Possible Selections– Honda CRV ($21)– Hyundai Tucson ($18K)– Toyota RAV4 ($22K)

∀ α = min(cost)/cost (total = 2.69)– Honda CRV = 0.86 – Hyundai Tucson = 1 – Toyota RAV4 = 0.83

• Normalized α – Honda CRV = 0.32 (= 0.86/2.69)– Hyundai Tucson = 0.37 – Toyota RAV4 = 0.31

Car Selection - Safety Criteria

• Possible Selections– Honda CRV ($21)– Hyundai Tucson ($18K)– Toyota RAV4 ($22K)

• Using www.safecar.gov (5-point scale)– Honda CRV = 4.8– Hyundai Tucson = 4.8 – Toyota RAV4 = 4.6

• Normalized α – Honda CRV = 0.34 (= 4.8/14.2)– Hyundai Tucson = 0.34 – Toyota RAV4 = 0.32

Design and Brand Name Criteria

1 = Does not meet criterion; 5 = partially meets criterion; 9 = completely meets criterion

13.704629066Sum

0.5815520672.15443469125Toyota

0.3089956441.1447142430.513Hyundai

0.109452290.4054801330.20.3333331Honda

Design RatingGeometric MeanToyotaHyundaiHonda

Design and Brand Name Criteria

1 = Does not meet criterion; 5 = partially meets criterion; 9 = completely meets criterion

Analytical Hierarchy Process – Car selection

Sum = 1

Not much difference between different selections RAV4 happens to have the highest score The scores can be different depending on individual ratings What happens if COST is the most important criterion?

Assignment

• (due Monday Sep 7 – Email me the file). – Repeat the same Analytical Hierarchy Process for Car selection but

include operating cost (Fuel and insurance) and assume design style is divided into Interior and Exterior. Use excel. Have all your tables on different tabs

– List five favorite technologies or engineering subjects that you are interested in pursuing. Write 2-3 sentences about different applications your are considering for each technology. (add this to the Excel sheet)

• (due Monday Sep 14 – Bring a hard coy to class). – As a group discuss your Analytical Hierarchy Process for Car selection

and come up with a final decision matrix. Each group member must be prepared to elaborate on the final decision.

– As a team agree on five favorite technologies or engineering subjects that you are interested in pursuing. Write 2-3 sentences about different applications your are considering for each technology. Submit a hardcopy. Each group member must be prepared to elaborate on the final decision.