1. Spring Semester 2015 Lecture 7 Needs vs. Wants
ECE 396 – Senior Design I
Spring Semester 2015
Lecture 7
Needs vs. Wants

2. Needs Assessment Interact with customer to understand the problem
Non-technical (avoid using excessive technical jargon)
Qualitative (no numerical information)
Complete (should cover all relevant aspects)
Specifiable (subjective need -> specification)
Questioning the customer
Questionnaire?
What kinds of questions should you ask?

3. Define the Design Problem
What is the problem to be solved?
Why is there a problem?
What is my (team’s) role in solving problem?
How will I know when I (we) are done?

4. Determine the Budget and Schedule Constraints
When is the solution needed?
What is the upper limit of the design cost?
What are your expectations of production cost (in high volumes)?

5. Determine the Reliability and Maintenance
What are the consequences of the system failing once in operation?
What resources (personnel, replacement parts, budget, etc.) are available for maintenance?

6. Determine the Design Contract
How will it be determined when the design is complete?
How will it be determined that the design is acceptable?
How will I be paid?
Is the work that I am doing legal?

7. Needs vs. Wants
It is quite a challenge to determine product features just from a customer survey
Ability to differentiate needs and wants is key to product development (usually wants >> needs)
Product should only have the essential needs
If we have excessive number of needs
Some needs may not be met -> bad design
Unnecessary needs -> additional cost

8. Input/Output Analysis
A good way to conceptualize design problem is the use of block diagrams
List of inputs (user, sensor)
List of outputs (user, control)
I/O analysis should help design the user interface

9. Engine Controller Unit (ECU)

10. Design Attributes Standard & Advanced functions User Interface
Packaging
Battery (power requirements)
Production
Reliability (robust design)
Service and maintenance

11. Conflicting Needs
Even in the best of designs you will have a set of conflicting design needs
Classic design conflict
Performance, cost, time
Good, cheap, fast (cannot have all three)
Size, power requirements, reliability, advanced features