P09701: Corning Tropel LightGage Metrology System

Identify Customer Needs

Table of Contents

Step 1. Gathering Raw Data From Customers

This 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:

  1. What type of precision would you like to get out of this project, and is it something that RIT students can realistically attain?
  2. How open are you to different architectures/approaches to solving this problem? Are there standard approaches C.T. takes to this type of problem?
  3. Intellectual Property: How do you plan on handling this? Will RIT students have to sign non-disclose agreements?
  4. Is this a "critical path" project that needs to be completed on a strict time line?
Note: These questions are answered below.

Second Interview/Meeting

Customer 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

Received Documents:

The following is the information gathered beyond what is posted in the Corning Tropel paper (link above):

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

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

  1. 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.
  2. 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.
  3. 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)
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. 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.
  10. 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).
  11. 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 Grouping

The following are the results of the needs affinity grouping process, as detailed below and in the Eppinger text (p.64).
  1. Each need statement was written on a separate post-it note and stuck to the wall.
  2. The cards were grouped according to the similarity of the needs they express. Duplicates were eliminated at this point.
  3. A label was chosen for each group (below).
  4. Supergroups were created (below).

3 b. Need Hierarchy Emerges

End of Needs Hierarchy

3 c. Preliminary Objective Tree


Step 4. Establishing Relative Importance of the Needs

The 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.
Needs Summary
Need Description Importance Tech. Spec.?
1.1 Low Complexity 1
1.2 Low parts cost 2 yes
1.3 Easy to maintain/work on 1.5
1.4 Small package 3 yes
1.5 Manufacturing Documentation critical yes
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
3.2.2b Vibration isolation critical
3.2.2c Repeatable part placement 1.5 yes
3.2.2d Light canceling/polarity critical

Step 5. Reflect on the Results and the Process

Other Things to Consider

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