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Concept Generation and Evaluation - Coggle Diagram
Concept Generation and Evaluation
Pugh’s Method for Evaluation
Selecting a
Design Requirement
A set of alternatives believed to satisfy the set of criteria
A means to evaluate the design alternatives with respect to each criterion
A set of design selection criteria.
Decision Making Behavioral Aspects
Making a decision is a stressful situation for most people because there is no way to be certain about the information about the past or the predictions of the future.
This psychological stress arises from at least two sources:
Decision makers are concerned about the material and social losses that will result from either course of action that is chosen.
They recognize that their reputations and self-esteem as competent decision makers are at stake.
Behavioral psychology provides an understanding of the influence of risk taking in individuals and teams
Decision
Making Challenges
Defensive avoidance:
Evade conflict by procrastinating, shifting responsibility to someone else, and remaining inattentive to corrective information
Hypervigilance:
Search frantically for an immediate problem solution.
Unconflicted change:
Uncritically adopt whichever course of action is most strongly recommended.
Vigilance:
Search painstakingly for relevant information that is assimilated in an unbiased manner and appraised carefully before a decision is made.
Unconflicted adherence:
Decide to continue with current action and ignore information about risk of losses.
Way to Achieve Good Decision
The alternatives are evaluated against the objectives.
The choice of the alternative that holds the best promise of achieving all of the objectives represents the tentative decision.
Alternative actions are developed.
The tentative decision is explored for future possible adverse consequences.
The objectives are classified as to importance.
The effects of the final decision are controlled by taking other actions to prevent possible adverse consequences from becoming problems and by making sure that the actions decided on are carried out.
The objectives of a decision must be established first.
Absolute Criteria Design Selection
Evaluation based on assessment of technology readiness
Product design is not the appropriate place to do R&D.
Evaluation based on go/no-go screening of the constraints and threshold levels of engineering characteristics
Evaluation based on judgment of functional feasibility of the design
Concepts should be placed into one of the followings:
Feasible
Not Feasible
Will Work
Pugh Method Concept
A particularly useful method for identifying the most promising design concepts among the alternatives generated at is the Pugh chart.
Pugh Chart is a relative comparison technique.
Pugh Chart
Steps
4) Choose the datum concept
5) Complete the matrix entries
3) Clarify the design concepts
6) Evaluate the ratings
2) Formulate the decision matrix
7) Establish a new datum and rerun the matrix
1) Choose the criteria by which the concepts will be evaluated
8) Examine the selected concept for improvement opportunities
Concept Generation Method
INTRODUCTION
A concept is an idea that is sufficiently developed to evaluate the physical principles that govern its behavior
Methods can be used to generate the design concepts:
Brainstorming
Synectic
Finding idea in reference books and journals
Using experts to help generate the concepts
Problem Solver Characteristic
Sensitivity: Ability to recognize that a problem exists
Fluency:The ability to produce a large number of alternative solutions.
Flexibility:The ability to develop a wide range of approaches to a problem
Originality: The ability to produce original solutions to a problem.
Brainstorming concept
Common Method Used By Design Teams For generating ideas.
General Usage the language to denote any kind of idea generation.
tips:
Criticism Is Not Allowed
Ideas Should Be Generated By The group
Generate as many ideas in short time
Participation
Brainstorming Way of sorting ideas
Ideas that are feasible as they stand
Ideas that may have potential after more thought or research are applied
Six Key Questions:
Who? What? When? Where? Why? How?
Synectics Concept
In design, like in everyday life,many problems
Recognizes Four Types Of Analogy:
1.Direct Analogy
2.Fantasy Analogy
3.Personal Analogy
4.Symbolic Analogy
Synectics Biomimetic concept
A particularly intriguing source direct analogies is those that are inspired by biological systems.
the mimicking of biological system such as:
1.Velcro Fasteners 2.Honeycomb Structures
challenge for designers is two fold:
Engineering designer are not trained in a wide variety of biological systems
the words engineers use to express behavior do not always match words used to describe biological systems.
Concept Map
Tool for the generation of ideas by association,and for organizing information in preparation for writing a report.
Good for generating and recording ideas during brainstorming.
Creativity Techniques for a Design Concepts
The motivation for applying any Creativity technique to a design task is to generate as many ideas as possible.
Quantity counts above quality, and wild ideas are encouraged at the early stages of the design work.
The team is identifying a smaller subset of ideas that can be developed into practical solutions.
Concept of Functional Decomposition and Synthesis
Common strategy for solving any complex task or describing any complex system is to decompose it into smaller units that are easier to work with.
Decomposing must result in units that meaningfully represents the original entity.
Functional decomposition method has solution-neutrality:
It does not initially impose a design, allowing more leeway for creativity and generates a wide variety of alternative solutions.
Functional Decomposition Description
Produces a diagram called a function structure.
A function structure is a block diagram depicting flows of energy, material, and signal as labeled arrows taking paths between function blocks.
This type of function structure (a single function block) is called a black box representation of a device.
Functional
Synthesis
Strength
First, creating function structures forces representation into a language that is useful for the manipulation for mechanical design problems.
Second, using a function structure to represent a design lends functional labels to potential solution components, and these labels serve as hints for new memory searches
Weakness
Some products are better suited to representation and design by functional decomposition and synthesis than are others
The function structure is a flow diagram where flows are connecting different functions performed by the product the structure represents.
Morphological Methods
Concepts
Method for representing and exploring all the relationships in multi dimensional problems.
Morphology means the study of shape and form.
Morphological analysis is a way of creating new forms.
Steps:
Step 2: for each function, list the means or methods to be used.
Step 3: Draw up the chart containing all the possible subsolutions.
Step 1: Develop concepts for each function
Step 4: Identify feasible combinations.