Identify Customer Needs
Step 1. Gathering Raw Data From CustomersThis node is where all of the information gathered from the Customer, all interviews, and all of the information-gathering processes are stored. All of the information used in building the PRP for P09701 is stored at this node.
Note that some of the information has been identified during the Project Status Update as belonging to "solution space" and is labeled as such. For the sake of completeness it has not been removed.
Interactions with Customers
First Interview/Meeting:RIT Faculty Sponsor Interview
Interview Objective: Gather preliminary information, customer contacts.
Participants: Matthew Bradley (interviewer), Dr. Wayne Walter
Date: 20 March 2008 @ 2:00PM, Dr. Walter's Office
Prepared Questions: Interview 1 Questions
- Interview Notes
This was the first interview since being assigned this project. I had prepared a number of questions for Dr. Walter assuming he had a decent understanding of what Corning Tropel wanted for this project. However, he did not have any knowledge of what the project entailed--just a simple description. He did give me a list of questions to ask Corning Tropel when I do interview them. He suggested I ask the following:
- What type of precision would you like to get out of this project, and is it something that RIT students can realistically attain?
- How open are you to different architectures/approaches to solving this problem? Are there standard approaches C.T. takes to this type of problem?
- Intellectual Property: How do you plan on handling this? Will RIT students have to sign non-disclose agreements?
- Is this a "critical path" project that needs to be completed on a strict time line?
- Note: These questions are answered below.
Second Interview/MeetingCustomer Interview @ Corning Tropel
Interview Objective: Identify customer needs, gather background information, identify stakeholders.
Participants: Matthew Bradley (interviewer), Thomas J. Dunn, Ph.D., Senior Optical Engineer
Date: 27 March 2008 @ 1:30PM, Corning Tropel Corporation
Prepared Questions: Interview 2 Questions
- Interview/Meeting Notes
- Here is Corning Tropel's draft needs/project request: RIT LightGage Notes Rev.B
- Here is the a LightGage Tech overview prepared for RIT: LightGage Tech. Overview
The following is the information gathered beyond what is posted in the Corning Tropel paper (link above):
- RIT MSD is being asked to participate in the development of the 2nd generation LightGage product
- It is crucial that mechanical drift be minimized--that is, if using motors, they must not move during the measurement process, and materials with very low coefficients of thermal expansion must be used.
- Must get the smallest possible gap between the top surface of the part and the Fizeau window on the head of the LightGage.
- Trial parts may be provided to MSD team if needed.
- Ideally, the design will be motored, but the customer is open to different architectures.
- Intellectual Property rights will need to be discussed prior to this project becoming a MSD project.
Interview Outcome: Enough information has been gathered to move on to the next step, Interpreting Raw Data in Terms of Customer Needs.
Third Interview/Meeting:Final DPM Meeting with Customer @ Corning Tropel
Meeting Objective: Review and refine mission statement, customer needs, make sure technical details were correct, answer some final questions, status update.
Participants: Matthew Bradley; Thomas J. Dunn, Ph.D., Senior Optical Engineer; Mark Tronolone, Software Engineering Manager
Date: 18 April 2008 @ 10:00AM, Corning Tropel Corporation
Prepared Notes: Meeting 3 Objectives/Questions (4/16/08)
- Interview/Meeting Notes
- Needs were refined. Note an additional need was added to Step 2.
- Needs Summary rankings revised, updated
- Discussed Resources
- All material, software, motor, costs associated with designing/building will be covered by Corning Tropel.
- MSD team will have access to LightGage for testing. By the time this project makes it to MSD1, there is a good chance the students will be able to acquire a LightGage stand to work on @ RIT.
- Corning Tropel Engineers will be available in a limited capacity to aid in parts/hardware/software integration.
- It is suggested that an EE with strong software/computer skills be chosen to aid in integration, debugging, etc.
- It is very unlikely that students will have to sign NDAs for this project. This will be worried about if the need arises. Likewise, it is highly unlikely that IP will be created in this process, so this will be addressed as needed.
Interview Outcome: The customer approves of PRP, needs have been revised and finalized, rankings established, and technical background screened for accuracy. All unanswered questions have been addressed and resources established. PRP can move on to final phase.
Step 2. Interpreting Raw Data in Terms of Customer Needs
- Accommodation of Part Thickness Variations: Since part thickness varies for different applications, it is important that the spacing between heads be motorized in order to accommodate part thicknesses ranging from 1mm to 100mm.
- Minimized Air-Gap: It is critical that the air-gap between the Fizeau surface and the part be as small as possible. The maximum measurement resolution is directly proportional to the space between the measured surface and the Fizeau surface.
- Balance Ease of Use with Accuracy: The larger the gap between the part surface and the top sensor, easier LG is to use. However, if the air gap is large, the accuracy of the measurement will be compromised. Thus, a balance between ease of use and measurement accuracy must be found in this design. (Added 4/20/08)
- SOLUTION SPACE! Tightest Mechanical Loop Possible: Due to the need for extremely accurate measurements, minimizing the mechanical loop will minimize possible mechanical drift, and in doing so, minimize error.
- Vibration Isolation: Vibration can cause severe deviation in measurements and repeatability. The fixture must be able to isolate and eliminate any external "noise." This constraint is critical.
- Light Polarity: When aiming two metrology heads at one another, stray light or light not reflected by the part can be captured by the opposing head, resulting in loss of accuracy. Because of this, the system has to account for this by aiming orthogonal polarized light at the second head. This feature will need to be adjustable for specialized conditions.
- Repeatability: It is expected that the part being measured could be removed from the device and then re-measured producing consistent results within a given range of tolerance. This is extremely important.
- Ease of Use: Whether the device is located on a factory floor or in a lab environment, the system and fixturing must be able to be effectively and efficienty serviced and operated by an operator of virtually any skill level. Creating a system that is easy to use would also impact the overall efficiency of use and customer part measurement throughput.
- Robustness: Various part shapes, materials, and surfaces must be accommodated by the fixture. Likewise, many of the materials under measurement may be fragile. The system would need to be able to handle delicate parts without damaging or compromising their integrity and regions of interest. One of the main marketing factors of the device is its ability to measure an extremely wide variety of materials, features, and sizes. It is expected that this device be able to measure virtually any part that the first generation LightGageTM could measure.
- Setup Speed: As discussed in the ease of use section, the overall setup speed of a dual-head system must have minimal human interaction and limited physical setup time (ie. seconds).
- Design for Manufacturing: Due to the commercial nature of the device, the fixture must be able to be manufactured reasonably inexpensively with limited reliance on custom parts. The use of off-the-shelf components is optimal to keep costs to a minimum. It is also projected that this system would be outsourced to another company for assembly. A detailed set of instructions on how to assemble and operate the device, with photographs (in standard Corning Inc. form) would be expected from the design team.
- Note: This section is largely based on RIT LightGage Notes Rev.B
Step 3. Organizing Needs into a Hierarchy
3 a. Affinity GroupingThe following are the results of the needs affinity grouping process, as detailed below and in the Eppinger text (p.64).
- Each need statement was written on a separate post-it note and stuck to the wall.
- The cards were grouped according to the similarity of the needs they express. Duplicates were eliminated at this point.
- A label was chosen for each group (below).
- Supergroups were created (below).
3 b. Need Hierarchy Emerges
1.0 Easy to manufacture @ a reasonable
- 1.1 Low complexity
- 1.2 Low parts cost
- 1.3 Easy to maintain and work on
- 1.3.1 See low complexity
- 1.4 Small package
- 1.5 Manufacturing documentation for outsourcing (to Corning standards)
- 2.0 High efficiency and throughput
3.0 Part Measurement and Accuracy
- 3.1 Part manipulation/control
3.1.1 Method of holding parts in place
- 3.1.1a Can hold/measure any part that LG gen. 1 could
- 3.1.2 Motorized LightGage head positioning
- 3.1.3 Measure both sides of part (critical)
- 3.1.4 Manual position control/override?
- 3.1.1 Method of holding parts in place
- 3.2 Measurement Accuracy
- 3.2.1 Very low mechanical drift
- 3.2.2 High measurement precision/accuracy
- 3.1 Part manipulation/control
End of Needs Hierarchy
3 c. Preliminary Objective Tree
Step 4. Establishing Relative Importance of the NeedsThe following table rates what were interpreted as some of the most important customer needs (excluding lower-level needs) on a scale of 1-5, 1 being highest priority and 5 being the lowest. Those needs that were determined to be absolutely critical are labeled as such. The content of this table and the ratings are subject to change pending further interaction with the customer.
|1.2||Low parts cost||2||yes|
|1.3||Easy to maintain/work on||1.5|
|2.1||Ease of use||critical|
|2.1.2||Short setup time||critical||yes|
|2.2||Fast part measurement||1||yes|
|2.2.1||Quick turnaround between part meas.||critical||yes|
|3.1.1||Method of holding parts in place||critical|
|3.1.1a||Can hold any part that LG gen.1 could||2|
|3.1.2||Motorized LightGage head position||3|
|3.1.2b||Accommodate part thickness from 1mm-100mm||critical||yes|
|3.1.3||Measure both sides of part||critical|
|3.2.1||Very low mechanical drift||critical||yes|
|3.2.2a||Smallest air gap possible between LG head and part sfc.||1|
|3.2.2c||Repeatable part placement||1.5||yes|
Step 5. Reflect on the Results and the Process
Other Things to Consider
- One of the challenges of this project will be satisfying need #3 in step 2. It is very important that the team focus on finding a balance between ease of use and measurement accuracy. As has been stated above, the distance between the Fizeau window and the part surface is very important. The part must be close enough to the Fizeau so as to yield accurate measurements, but not so close that it may hit or damage the sensor. Furthermore, depending on the design, getting a very tight gap may mean sacrificing ease of use--something the customer is not willing to do. Because of this, meeting 3 established a tolerance for this gap. For our purposes, the gap should be between "a couple millimeters, but no more than 10mm." Consider this a tech. spec.