ME 102B Concept Selection
Important Issues - Concept Selection
The goal is to choose the best of the concepts for development into
products while expending the least amount of resources.
How can the team choose the best concept, given that the designs are still
How can a decision be made that is embraced by the whole team?
How can desirable attributes of otherwise weak concepts be identified and
Use some methods for choosing a concept
External Decision: Concepts are turned over to the customer,
client or some other external entity for selection.
Product Champion: An influential member of the product development
team chooses a concept based on personal preference.
Intuition: The concept is chosen by its "feel". Explicit
criteria or trade-offs are not used. The concept just "seems" better.
Pros and Cons: The team lists the strengths and weakness of each concept
and makes a choice base upon group decision.
Prototype and test: The organization builds and tests prototypes of each
concepts, making a selection based upon test data.
Decision methodologies: This may include technology assessment, screening
and decision matrices.
Benefits of Structured Methodologies
A customer-focused product Because concepts are explicitly evaluated
against customer-oriented criteria, the selected concept is likely to
be focused on the customer.
A competitive design: By benchmarking concepts with respect to
existing designs, designers push the design to match or exceed their
competitor's performance along key dimensions.
Better product-process coordination: Explicit evaluation of the
product with respect to manufacturing criteria improves the product's
manufacturability and help to match the product with the process
capabilities of the firm.
Reduced time to product introduction: A structured methodology
becomes a common language among design engineers, manufacturing engineers,
industrial designers, and project managers, resulting
in decreased ambiguity, faster communication and fewer false starts.
Effective group decision making:
Within the development team, organizational philosophy and
guidelines, willingness of members to participate, and team member experience
may constrain the concept selection process. A structured methodology
encourages decision making based on objective criteria and
minimizes the likelihood that arbitrary or personal factors influence the
Documentation of the decision process:
A structured methodology results in a readily understood archive of the
rational behind concept decisions. This record is useful for assimilating new
team members and for quickly assessing the impact of changes in the customer
needs or in the available alternatives.
Prepare the selection matrix
Rate the concepts Use a datum and rank as follows:
+ Better than datum
0 Same as datum
- Worse than datum
Rank the concepts
Score each concept by subtracting number of "-" from number of "+" then
rank concept on basis of highest sum.
Combine and improve the concepts
Is there a generally good concept which is degraded by one bad feature?
Can a minor modification improve the overall concept and yet preserve a
distinction from the other concepts? Are there two concepts which can
be combined to preserve the "better than" qualities while annulling
the "worse than" qualities?
Select the set of highest potential concepts for further screening
Concept Scoring is used to increase resolution and better differentiation
among competing concepts
Prepare the selection matrix
Add more selection criteria, add weights (could be from QFD)
Rate the concepts
Use rating system: 1-Much Worse; 2-Worse; 3-Same; 4-Better; 5-Much Better
Extra money customer willing to pay for improvement
- Extra money feature will cost to give (- if cost saving)
Rank the Concepts
Multiply each rate by weight; sum each design for total score; rank
concepts on basis of highest sum.
Combine and improve concepts
Is there a generally good concept which is degraded by one bad feature? Can a
minor modification improve the overall concept and yet preserve a distinction
from the other concepts? Are there two concepts which can be combined to
preserve the "better than" qualities while annulling the "worse than"
Select one (or a small set) of designs to develop