Stakeholder and Needs
What is a stakeholder?
A stakeholder is any individual or group who has an interest in or is affected by a product (users, customers, manufacturers, regulators, etc.).
What are the key characteristics of a good engineering requirement?
1. Correct: Needs to be an actual requirement, relate to needs
2. Feasible: Is it possible given known physics, technology, etc.?
3. Necessary: Is this an actual need?
4. Unambiguous: Does it have one clear meaning for a knowledgeable person?
5. Verifiable: Can you develop a test of some sort that will lead to a pass/fail
result?
6. Open: Should not automatically lead to one defined solution
What is the purpose of ideation?
To generate many possible solutions before selecting one.
What is a functional representation?
A diagram showing functions and flows (energy, material, signal) without listing physical components.
What does gear ratio represent?
Ratio of output speed to input speed (or teeth ratio between gears).
Name 3 methods for identifying stakeholder/customer needs.
Interviews
Surveys
Observations
Focus groups
Ethnographic studies
Market research
What is wrong with this requirement?
“The device should have a rechargeable battery that lasts at least 8 hours and is fully charged in less than 2 hours.”
“Should” is weak wording
Two requirements combined into one
Not fully specific about conditions
Better version:
“The device shall operate continuously for ≥8 hours at 100% load and recharge to 100% capacity within ≤2 hours using a 120V AC outlet.”
Name 3 ideation methods.
Brainstorming
SCAMPER
Mind mapping
6-3-5 method
Morphological analysis
Name the 4 Cs of form generation.
Constraints
Configurations
Connections
Components
Given
NA = 35
NB = 20
NC = 25
ND = 10
ωA = 20 rpm
Find gear train ratio and ωD.
For compound gear train:
Gear ratio = (NB/NA) × (ND/NC)
= (20/35) × (10/25)
= (4/7) × (2/5)
= 8/35
ωD = ωA × (1 / gear ratio)
= 20 × (35/8)
= 87.5 rpm
What are the three general categories of customer needs in the Kano Model?
basic needs
Performance needs
excitement needs
What is the main purpose of the House of Quality?
To translate customer needs into engineering requirements and evaluate relationships between them.
What is a morphological chart used for?
To systematically combine different solution methods for each function to generate new concepts.
What are constraints?
Limitations such as cost, size, regulations, materials, manufacturing capability.
What does Gruebler’s Equation determine?
The degrees of freedom (mobility) of a mechanism.
List 5 stakeholder needs for a new adult water bottle and classify each.
Keeps water cold for 12 hours – Performance
Does not leak – Basic
Fits in car cup holder – Performance
Dishwasher safe – Performance
Built-in hydration tracker – Excitement
Name the major sections of the House of Quality.
Customer needs (WHATs)
Engineering requirements (HOWs)
Relationship matrix
Correlation roof
Competitive benchmarking
Target values
Difference between a Pugh chart and Weighted Objectives Model?
Pugh: compares concepts to a baseline (+, 0, −)
Weighted objectives: assigns numerical weights and scores
What does configuration refer to?
The spatial arrangement and layout of components in the system.
What is the difference between Grashof and non-Grashof mechanisms?
Grashof: at least one link can fully rotate.
Non-Grashof: no link can fully rotate.
Grashof condition:
s + l ≤ p + q
Why are stakeholder needs important in engineering design?
They drive engineering requirements, reduce risk of failure, ensure customer satisfaction, and align the product with market demand.
How does the House of Quality guide decision making?
It prioritizes engineering requirements based on customer importance and shows trade-offs between technical parameters.
When would you use a Pugh chart instead of weighted objectives?
Early-stage screening when criteria are qualitative and quick comparison is needed.
Why is understanding connections important in detailed design?
It affects manufacturability, assembly, maintenance, strength, and reliability.
Why do we care if a mechanism is Grashof?
It determines whether continuous rotation is possible (important for motors and continuous actuation).