Lesson Plans: The Engineering Conceptual Design Phase

Topic 6 Conceptual Design
(detailed objectives) (available resources)
Goal: Students exercise the conceptual design phase of a real project from problem definition to evaluation of the conceptual design alternatives.
[standards: NS.5-12.5]

(to review the detailed content, download the low resolution pdf of available teacher presentation)
Summary
This topic seeks to guide the team around some common temptations that novice designers succumb to. Designers' success can be undermined by preconceptions, hasty decisions, and personal biases. Additionally, team environments require special attention to maintain the support of all team members. There are some easy to implement ploys to circumnavigate these pitfalls in a team environment. Though it takes more time, the design team is more likely to choose a good solution strategy.

Background
Novice designers are often plagued by the tendency to adopt the first idea that comes to mind. Expert designers realize that rarely does the best idea come easily. The expert designer also realizes that the root problem may not be the problem as it is initially presented to them. Diligently identifying the true problem and searching for the broadest possible range of solution alternatives is the best way to ensure that your final solution is a relatively good one.

The goal of the conceptual design phase is to identify the very general type of solution that will be pursued. If the challenge is to "communicate a message," the conceptual decision is NOT whether to use a pen or a pencil. The conceptual decision is what type of communication media to use video, audio, written, or even smoke signals. If "written communication" is the chosen conceptual solution path then later, in the embodiment phase, you would choose what language and what tools to use (pen and paper, e-mail, or perhaps classified ads). Finally in the detail design phase you might choose a #2 pencil, standard notebook paper, and cursive writing. (Note this curriculum combines the embodiment and detail design phases for the sake of simplicity)

A prerequisite to choosing a good conceptual solution path is to make sure you are addressing the correct problem. In this example, "communicate a message," there are a lot of questions that should be asked regarding the nature of the message, the intended audience, and the resources at hand. The childhood message "I like you, do you like me?" probably warrants the pencil and notebook paper embodiment solution. Whereas the adult message "I love you, will you marry me?" might warrant a jumbotron at a sporting event or a banner trailing behind a plane...neither of which would work if the intended audience can't read. To maximize the chance of achieving a good solution, one must understand the problem and the imposed constraints.

Expert designers understand the difference between an abstract concept and a specific design. Beginning designers are unlikely to appreciate the difference nor will they necessarily be equipped to intuitively breakdown a complex challenge into constituent parts. For this reason, this topic uses a modified protocol aimed at using students' specific ideas to derive abstract functional requirements and conceptual solution alternatives.

The final area of concern addressed in this topic is how a team should make decisions. Most believe that we in the USA live in a democracy. That is not entirely true. We do have a representative form of government where "everyone" has an equal vote. However, decisions made by our representatives may or may not represent the majority of the people at that time. In your class you can choose to impose true democratic rule, but you will have the same problem that is felt on the national stage. Those in the minority will often resent the decisions that are made and may not work to support the team. Instead of majority rule, encourage consensus on all decisions. Consensus means finding a solution that every single member of the team will work to support. Though you will occasionally find an individual who refuses to compromise, generally ideas can be combined and re-formed into ideas that the entire team can completely support without losing the contributions of the minority.

Beyond learning how to reach concensus, all designers should learn ways to overcome personal attachment to specific ideas. One way to eliminate personal biases (or at least reduce them) is to utilize a mathematical decision matrix to choose between alternatives. Even if biases are not "strong," a decision matrix helps to weigh complex decisions (when many different factors must be considered). You'll find that it is easier to evaluate and compromise on a single decision (a single number in the matrix) than to readily accept that another idea is across the board better than your own "favorite." Using a mathematical decision matrix changes the rejection of an idea from "my idea is not as popular as others" to "mathematically my idea scored a lower than others and it's favorable qualities should be incorporated into the higher scoring ideas." It will also provide clues as to what favorable characteristics of various rejected ideas should be incorporated into the chosen idea. To create a decision matrix:

Identify the alternatives and list them in the first column
Identify the significant factors or criteria and list them across the top
Assign weights to each factor (total should equal 100)
Rate each alternatives against each factor (only use max value, medium values, or zero)
Total the score for each alternative to identify leading candidates and least likely candidates

Teacher Preparation

Contrive a design challenge that is roughly equivalent to the class project. Prepare a good problem statement and function structure for the example.
Prepare an example design matrix for the example problem.
Prepare handouts to define brainstorming rules, definitions relevant to the conceptual design phase, and how to create a decision matrix.
Contrive some situations where generating a otherwise good specific solution to the wrong conceptual problem is not a desirable outcome.

Classroom Activities
The students should be introduced to their class project and encouraged to openly discuss their initial impressions and inclinations on how to solve the problem. Then begin to describe to them the difference between conceptual and specific ideas and the potential pitfalls if the steps in the formal design method are not followed. (Specifically, those that insist of defining the problem well and choosing a conceptual solution without bias towards a specific preconception). Use your example design to lead the class through defining the problem, searching for solution alternatives, and choosing the best solution for thier class project. Use a mix of individual effort, small group effort, and full team discussions to keep all students actively engaged.

Objectives 6.1 An Abstract Problem Statement and Function Structure Distinguish between abstract solutions and specific solutions Comprehend the importance of removing all designer biases and preferences in the problem definition phase Compare and contrast our modified design process with a typical expert design process Comprehend the elements of a good problem definition Comprehend possible hazards of not developing a good problem statement	Activities (may take 2 class meetings) Students discuss the underlying objectives of their engineering project challenge. Engage students with teacher presentation. Small group discussions to draft a problem statement and function structure. Class discussion to create a good problem statement. Class discussion to create a good function structure
6.2 Search for Conceptual Solutions Comprehend basic goals of the brainstorming method Know basic rules of brainstorming Comprehend the distinction between "solution concepts" and "types of solution concepts"	(may take 2 class meetings) Small group brainstorming. Class discussion to organize and classify brainstorming ideas.
6.3 Defining Design Factors Comprehend that there are usually multiple factors by which to evaluate alternatives Deduce important "Design Factors" from characteristics that distinguish various alternatives	(may take 2 class meetings) Individually evaluate solution alternatives. Class discussion to list advantages and disadvantages of solution alternatives. Class discussion to create important design factors. Class discussion to assign a significance rating to each factor.
6.4 Decision Matrices Comprehend the basic goal of a decision matrix Know the components of a decision matrix Comprehend how to complete a decision matrix Comprehend how to interpret a decision matrix	(may take 2 class meetings) Engage students with teacher presentation. Class discussion to complete a decision matrix.
6.5 Combining Ideas and Choosing a Final Solution Path Distinguish a good problem statement from an overly vague statement Distinguish a good problem statement from a biased problem statement Distinguish between a solution to a function and a solution to a sub-function	Class discussion to develop final problem statement and final function structure. Small group brainstorming. Class discussion to combine and narrow alternatives. Class discussion to create a decision matrix and determine final solution path.
Additional resources available to licensed users: In addition to 38 animated PowerPoint customizable slides...
Student Resources Supplemental reading materials (printable or web linked)	Practice and Assessment Templates Students are heavily engaged with major project... Template for assessing learning objectives