Lecture 5 Product specifications.
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Email Homework Assignment Go through the process describe in the lecture (and text) with your team. Email me with the following,
Description of the customer for your project, The questions you would like to ask this customer, The customer responses that you think the customer would give, and, The interpreted customer needs that you determined. The method of prioritizing the needs that you used.
ECEn 490 – Fall 2008
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Identifying customer needs. Homework assignment
•What were some of the challenges in coming up with customer needs? How did some of you arrive at a definition of your customer?
•What were some of the 5 top needs as identified by your process? •How will you use these needs in developing your product?
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Concept Development Phase
Phase 1 Concept Development Phase 2 System-Level Design Phase 3 Detail Design Phase 4 Testing and Refinement Phase 5 Production Ramp-up
Mission Statement
Identify Customer Needs Establish Target Specs Generate Product Concepts Select a Product Concept Test Product Concept Set Final Specs
Development Plan
Plan Downstream Development
Perform Economic Analysis Benchmark Competitive Products Build and Test Models and Prototypes
Concept Development
Exhibit 3 Chapter 5 Ulrich & Eppinger
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Needs and Specifications
Customer Needs describe What the end product or service does for the user. They are expressed in the “language of the customer”. The “product__________” Product Specifications allow quantification of the customer needs. The Specification has both a metric and a value. The Product Metrics describe the measures used to determine IF the product meets the required needs. The Value is the actual numeric specification that the designers use to determine when the product meets the customer requirements. yes Successful Metrics/ IF What Product Values no
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Example: Specialized mountain bike design. Customer need: The Suspension enables high-speed descents on bumpy roads. Product Metrics: 1. Attenuation from dropout to handlebar at 10 Hz. 2. Maximum value from the Monster (suspension test by Mountain Bike Magazine.) 3. Minimum descent time on test track. Note: the metric does not yet have an actual value assigned at this point. Why not?
Product Specifications usually require a preliminary product definition.
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Importance of Clear Specifications
• Product Specifications are the “blue prints” of a project. They will guide the project throughout the development.
• Developing product specifications is a two step process. •Step 1 establish target specs to help channel the thinking during the product concept generation process. (Usually requires making assumptions as to what the final product configuration will be.) •Step 2 is the refinement of the specifications once the team has picked a product concept and is ready to go into system level design. Completed after concept selection.
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Process for Establishing Target Specifications
1. Prepare the list of Metrics based on your customer needs. 2. Establish what “best in class” products would require. Collect competitive benchmarks if available. 3. Set the target values for each metric 4. Reflect on the results
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The process of developing product specifications begins with your completed matrix of interpreted customer needs. Again note that there are no values.
# 1 Can win
Customer Need Statements
Interpretation of Needs
Robot can score more goals than opponent
Imp .
4
2
Can control the ball while moving
Robot can maintain possession of the ball while moving Robot has simple design so as to facilitate functionality void of problems
Robot positions itself between its goal and the ball to prevent a goal Robot is able to shoot the ball at different angles so as to score Robot is able to determine the position of the ball and its opponent
4
3
Want a simple design
4
4 5
Can block shots Robot is able to score from anywhere on the field Able to determine position of ball and opponent
4 4
6
4
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Customer Needs lead to Product Specs
The Customer expresses the need in terms of What the product must do.
The robot can quickly change alignment without forward motion.
The Product Specification sets metrics and values that allow quantification of the user need. The Robot can rotate 360 degrees in 2 secs without forward motion .
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A Product Spec for each Need
– Prioritize the Needs. It is important to identify the critical factors for success and make sure you have a way of quantifying these factors.
– Develop a measure and value for each need – Some needs may have more than one specification.
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Example of a customer needs table
# 1 Can win
Customer Need Statements
Interpretation of Needs
Robot can score more goals than opponent
Imp .
4
2
Can control the ball while moving
Robot can maintain possession of the ball while moving Robot has simple design so as to facilitate functionality void of problems
Robot positions itself between its goal and the ball to prevent a goal Robot is able to shoot the ball at different angles so as to score Robot is able to determine the position of the ball and its opponent
4
3
Want a simple design
4
4 5
Can block shots Robot is able to score from anywhere on the field Able to determine position of ball and opponent
4 4
6
4
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Example of a Product Specification table
Metric #
1
2 3 4
Need #
1
2 2 2
Metric
Goals scored minus conceded goals Distance from ball to robot
Units
Goals cm
Marginal Value
>0 <10
Ideal Value
>2 <2
Time from possession of ball Radius of circle made while in possession of ball at top speed Number of motors, circuits, batteries, moving parts
s cm parts
>10 >=50 <=12
>=30 >=10 <=6
5 6
3 3
Number of lines of code
Percentage of blocked shots given random speed and location of ball and robot Percentage of goals given random location of shot and opponent Maximum difference between calculated ball position and actual ball position Maximum difference between calculated opponent position and actual opponent position
lines
%
3000 >=50
1500 >=90
7
4
%
>=70
>=95
8
5
cm
<=5
<1
9 10
6 6
cm
<=5
<1
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Types of Metrics
– Some metrics are dependent, some are independent variables
• Independent metrics can be set by the designer, “number of motors”, “amount of battery time required” • Dependent metrics are the result of other design decisions, “mass of robot”, “size of the battery”
- It is important to identify the dependent variables to insure the other design choices don’t compromise the customer needs.
Examples for your project?
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Values of Metrics
1. At least X-- set a minimum amount,
2. At most X -- set a maximum,
3. Between X and Y -- set a range, 4. Exactly X -- set a fixed value,
5. Discrete values – parts are only available in discrete increments,
Are all needs quantifiable?
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Tools for transforming Needs into Specifications
– Needs-Metrics Tables – Quality Function Deployment- QFD – Competitive Benchmarking
Analyze Data vs. Requirements
measure
Correlate Requirements with Measures
ECEn 490 – Fall 2008
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Needs-Metrics Tables
Metric #
1
Need #
1 Goals scored minus conceded goals
Metric
Distance from ball to robot
Time from possession of ball Radius of circle made while in possession of ball at top speed
Units
Goals
2
3 4
2
2 2
cm
s cm
5
6 7
3
3 4
Number of motors, circuits, batteries, moving parts
Number of lines of code Percentage of blocked shots given random speed and location of ball and robot
parts
lines %
8
9 10
5
6 6
Percentage of goals given random location of shot and opponent
Maximum difference between calculated ball position and actual ball position Maximum difference between calculated opponent position and actual opponent position
%
cm cm
11 12
13 14
7 7
8, 18 9, 18
Maximum percentage error between calculated ball position and actual ball position per second
Average percentage error between calculated opponent position and actual opponent position per second Acceleration Mx speed
%/s
%/s m/s^2 m/s
15
16
10,25,27
11
Time elapsed from a change in the environment to a change in the robot's action
Whether or not a victory dance is implemented at the right time (ie after robot scores)
s
N/A
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Quality Function DeploymentQFD, or a Needs-Metrics Matrix
1
2 Distance from ball to robot
3 Time from possession of ball
4 Radius of circle while in possession of ball
5 Number of motors, batteries, moving parts
6
7 Percentage of blocked shots given random speed
8
Goals scored minus conceded goals
Number of lines of code
Percentage of goals w/random location of shots
Metrics
Needs
1 2 3 Robot can score more goals than opponent Maintain possession of the ball while moving simple design with functionality w/o problems
4 5
positions itself between its goal and the ball able to score from anywhere on the field
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Competitive Benchmarking
Metric # Need # Metric
Goals scored minus conceded goals 1 2 3 1 2 2 Distance from ball to robot Time from possession of ball cm s <10 >10 <2 >=30
Evaluate the competition
Marginal Value
>0
Units
Goals
Ideal Value
>2
Comp 1
3 4 8
Comp 2
1 1 15
Comp 3
-2 2.3 13
Comp 4
3 3 9
4 5 6
2 3 3
Radius of circle made while in possession of ball at top speed Number of motors, circuits, batteries, moving parts
Number of lines of code Percentage of blocked shots given random speed and location of ball and robot
cm parts
lines %
>=50 <=12
>=10 <=6
35 35
3000 35
5 8
2450 60
15 12
4000 50
27 24
1400 65
3000 >=50
1500 >=90
7
4 Percentage of goals given random location of shot and opponent % >=70 >=95 70 55 80 70
8
5 Maximum difference between calculated ball position and actual ball position cm <=5 <1 2 4 1 1.5
9
6
10
6
Maximum difference between calculated opponent position and actual opponent position
cm
<=5
<1
3
4
2
2
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In-Class Exercise
– Get into your teams – take the Interpreted Customer Needs from your homework assignment – develop 3-5 target product specifications for the product (both the metric and value) – Remember, you haven’t picked a final product concept yet– try keep the specifications in terms of “what” not “how” – be prepared to present your ideas to the class.
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Homework assignment
Complete the Preliminary Functional Specifications Document (PFSD) for your senior project. Use template illustrated in Example FSD on the website, or a similar format to capture the relationship between your customer needs and the product specs you will need meet in your design. Have the First pass available on your website and emailed to Prof. Clifford by next Thursday, September 25th. Read Chapter 6 Concept Generation
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The Four sections of the FSD
1. 2.
3.
Project Description and background: What is the project, and what is expected to be accomplished. Project Requirements: Who is the customer, and what are the interpreted needs and requirements including their relative importance. (customer needs table)
Product Specifications: The measurable engineering characteristics (metrics) and target values for the product.
4.
Linking of the Project Requirements and Product Specifications: The analysis of the specifications to insure that critical program and customer requirements are being met. (table showing needs, specs, and values)
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