Select Product Concept(s)
Table of Contents
We carried these steps out in full for the most complex problem, and then used an abbreviated method for the remaining concept selections.
Step 1. Prepare the Selection MatrixFrom our System Subfunction Solutions list, we drew our list of concepts for the problem of dispersing light energy.
Step 2. Rate the ConceptsEach concept was rated with either a (+), a (-), or a 0 for each of several selection criteria. A (+) meant that it was a superior concept to our reference, an (-) meant it was inferior, and a 0 meant it was comparable. For Light Dispersion, our criteria were
- Initial cost
- Ease of manufacturing
- Bulb replacement
- Light distribution, and
- Ease of installation
Once each concept was rated, a net score was found. Any concept with a negative net score was discarded, and we proceeded to step 3.
Step 3. Rank the ConceptsOur selection criteria were assigned a weighting based on our customer needs. We again evaluated our concepts relative to a reference concept, this time on a 5-point scale with 3 being equivalent to the reference. The ratings and weights were combined to produce a weighted score for the concept relative to the criterion. Finally, the weighted scores for each concept were summed, and the concepts ranked relative to each other.
Step 4. Combine and Improve the ConceptsOnce the concepts were ranked, we investigated them further to see if there were ways to modify them to improve their scores. For some concepts, there was a clear "winner" that we chose to continue with. For others, a combination of two or more concepts was found to be superior.
Step 5. Select One or More ConceptsFinally, one concept for each subfunction had to be chosen.
- For Light Dispersion, we chose to use Surface Mount LEDs and a directional placement of our LED boards.
- For Application of Electrical Energy, we found three equally valid concepts, and deferred the decision on which concept to use to after further benchmarking.
- For the Sensing/activation switch, we chose to pursue a zone photoeye on the main (the existing control system), combined with a motion sensor on the fixture.
- For the Power Supply Method, we chose to use the power grid, due to the efficiency gain inherent in switching from Metal Halide to LED lighting. We retained the solar power option to pursue if there is more time towards the end of SDII.