Evaluation of Alternative Concepts
Design Step 3
Project Exhibition Night: K.A.A.S Website
Important concepts to apply to your designs:
Minimize number of parts.
Minimize number of different Kinds of parts.
When possible buying parts (on the cheap!!!) is preferable to manufacturing them yourselves.
Seek a modular design (i.e a design where the different functions are physically isolated.)
Design for ease of manufacture.
Design for robustness.
Design for adjustability (thing can be tuned up on the fly to improve performance).
Design Milestone: Evaluation of Alternatives
*From STEM Engineering Website*
Use the matrix to identify and correct weaknesses in a promising design. Give priority to the weaknesses that are most heavily weighted.
Grading Criteria
• Are weights and values accurate and fully justified?
• Were the results of the decision matrix interpreted thoughtfully when searching for and selecting the best concept?
• Were all three concepts strong designs?
• Is the documentation typed and clearly written?
Things to Consider
• There is no need to rig the results of the decision matrix to come out to the concept you want as the results are nonbinding.
• Do not blindly obey the results of your decision matrix; the selection of evaluation criteria may have been flawed to begin with.
• Engage everyone in the decision-making process. including your mentors!!!
• Do not shy away from bold designs just because they are different from everyone else's. Those differences could lead to some serious innovation.
Best Possible Design
Design 2 is our best design because it ranked the highest possible for 3 out of our 5 different design criteria, had the highest overall score in our matrix, and should be relatively easy to construct if we get the parts we need. In terms of cost, the lighting on this system will be the most expensive because it needs to be a part of the tank, making the design overall more expensive. In geometry, because of the lighting, the tank is going to be more difficult to get because of price barriers or difficult to make due to our skillset, however if we get those materials (requested through the STEM fund), then it will be much easier. In terms of complexity, if we are able to buy a tank, this design will be much easier and the pipes vs. mesh pots simplify the design without cutting quality. In terms of customizability, the aesthetic for this system can be completely customized to user preference. And last, in terms of practicality, the size of this system will be the best because it allows for multiple plants to be grown at once and it takes up less vertical space than design 1.
Life Cycle Assessment (LCA)
Life Cycle Assessment (LCA) is a "cradle-to-grave" approach for assessing products, processes, industrial systems, and the like.
"Cradle-to-grave" begins with the gathering of raw materials from the earth to create the product, and ends at the point when all materials are returned to the earth.
LCA evaluates all stages of a product’s life from the perspective that they are interdependent, meaning that one operation leads to the next.
LCA enables the estimation of the cumulative environmental impacts resulting from all stages in the product life cycle and, as a result, allows selecting the path or process that is more environmentally friendly.
CA helps Design teams select the product, process, or technology that results in the least impact to the environment.
This information can be used with other factors, such as cost and performance data to find optimal solutions.
The diagram to the right illustrates the main lifecycle stages to be considered in LCA:
Reflection
During this project we were tasked to the alternative concepts brainstormed for our capstone design by using a matrix and quantifiable evaluation system. We took the aspects we had researched in Step 2 to evaluate all of them and determine to overall most successful module. In addition, we created a life cycles assessment with the goal of applying life-cycle thinking to our capstone product. It was also to help us map out all inputs and outputs, and identify the needed materials and processes as well as the potential environmental impacts of each lifecycle stage.
NGSS Standards:
NGSS.HS-ETS1-3 Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts.
DCI - ETS1. A Criteria and constraints also include satisfying any requirements set by society, such as taking issues of risk mitigation into account, and they should be quantified to the extent possible and stated in such a way that one can tell if a given design meets them. (secondary to HS-PS2-3)
DCI - ETS1.B When evaluating solutions, it is important to take into account a range of constraints, including cost, safety, reliability, and aesthetics, and to consider social, cultural, and environmental impacts. (HS.ETS1-3)
DCI - ETS1.C Criteria may need to be broken down into simpler ones that can be approached systematically, and decisions about the priority of certain criteria over others (trade-offs) may be needed. (secondary to HS-PS1-6)
Learning outcomes: Students will be able to:
Ask and/or evaluate questions that challenge the premise(s) of an argument, the interpretation of a data set, or the suitability of a design.
Evaluate merits and limitations of different models of the same proposed tool, process, mechanism or system in order to select or revise a model that best fits the evidence or design criteria.
Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design: decide on types, how much, and accuracy of data needed to produce reliable measurements and consider limitations on the precision of the data (e.g., number of trials, cost, risk, time), and refine the design accordingly.
Consider limitations of data analysis (e.g., measurement error, sample selection) when analyzing and interpreting data.
Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.
Design, evaluate, and/or refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and trade-off considerations.
We used our critical thinking skills to evaluate the various possible combinations of parts for our hydroponics tank. We also had to work on collaborating as a group and pitching in our various ideas and suggestions when creating the evaluation criteria. Overall this project was successful in giving us more information about how to proceed with our capstone project. Also, we now have a solidified design for our product and multiple alternatives to try during the prototyping process.