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

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?

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?

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)?

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?

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?

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

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

Engine Controller Unit (ECU)

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

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