Developing
Product Design Specifications
Chapter 5, Ulrich & Eppinger text
IDENT
OPP
DEFINE
PROBLEM
GEN
CONCEPTS
GATHER
INFO IMPLEMENT
SCREEN
CONCEPTS HANDOFF
ME 4054W Design Projects
January 26, 2012
UNIVERSITY OF MINNESOTA
When are product requirements established?
Identify
customer
needs
Establish
target
requirements
Generate
concepts
Select
concept
Refine
requirements
Detail design, test, prototyping
UNIVERSITY OF MINNESOTA
What is a Product Design Specification?
A Product Design Specification (PDS):
◦ Is a documented statement of what the product is to do
◦ Is a living document, but defined early
◦ Is driven by customer needs
◦ Shows what you are trying to achieve
◦ Contains:
List of Customer Needs
Design Specifications
UNIVERSITY OF MINNESOTA
Establishing Target Specifications
1. Prepare a list of metrics from the needs
2. Collect competitive benchmarking information
3. Set ideal and marginally acceptable target values
4. Reflect on the results and process
UNIVERSITY OF MINNESOTA
Metrics
The metrics should be:
– Complete
– Practical
– Expressed as a dependent variable (what, not how)
– Derived from a customer need
UNIVERSITY OF MINNESOTA
The vast majority of the metrics should be objective and numeric with units
◦ For example lb, $, inch, N-m, etc.
Metrics can also be subjective and binary.
◦ For example, “Aesthetically pleasing” and “Meets the ISO-xxxx Safety Standard”.
Metrics
UNIVERSITY OF MINNESOTA
Competitive Benchmarking
The relationship of the new product to competitive products is critical in determining its potential for success in the marketplace.
Having a product that is meaningfully better than its competitors on high priority needs creates differentiation and increases the likelihood of commercial success.
Gathering information on competing products is the best way to understand the relative position of the proposed product with respect to its competitors and helps to validate the specs.
UNIVERSITY OF MINNESOTA
Competitive Benchmarking
This is an abbreviated list. See Exhibit 5-6 in the text.
UNIVERSITY OF MINNESOTA
Target values
Targets are set by considering: ◦ Today’s competition
◦ Competitor’s future capabilities
◦ The product’s mission statement and target market segment
Targets can be expressed as: ◦ Exact (1.5 inches)
◦ Less than (< 1 inch)
◦ Greater than (> 1 inch)
◦ Range (1.5 – 2.0 inch)
◦ A set of discrete values (1.0, 1.5, 2.0 inch)
UNIVERSITY OF MINNESOTA
Example: Product Specifications for a
Bicycle Suspension Fork
This is an abbreviated list of product specs for the suspension fork. See Exhibit 5-8 in the text.
UNIVERSITY OF MINNESOTA
Establishing Target Specifications,
redux
1. Prepare a list of metrics from the needs
2. Collect competitive benchmarking information
3. Set ideal and marginally acceptable target values
4. Reflect on the results and process
UNIVERSITY OF MINNESOTA
Establishing Final Specifications
1. Develop technical models for the product
2. Develop a cost model of the product
3. Refine the specifications, making trade-offs where necessary
4. Flow down the specifications as appropriate
5. Reflect on the results and the process
UNIVERSITY OF MINNESOTA
Bottom Line
The design requirements in the PDS must:
– reflect customer need
– differentiate the product from the competition
– be technically and economically feasible
Sandy Cutler, CEO of Eaton, asks his engineers:
• Is the customer asking for it?
• What differentiation does it offer Eaton?
• What value does it offer the customer?