product concept selection - u of m: department of mechanical

Product Concept Selection

ME 4054W February 9, 2012 Prof. Bohlmann

Reference: Ulirich & Eppinger, Chapter 7

IDENTIFY OPPORTUNITY

DEFINE PROBLEM

GENERATE CONCEPTS

GATHER INFORMATION IMPLEMENT SCREEN

CONCEPTS HANDOFF

UNIVERSITY OF MINNESOTA

Product Concept Selection Attributes

• While concept generation is easy (and fun), concept selection is difficult (and fun)

• You never have enough information; you must make informed decisions nonetheless

• You will likely use estimation, analysis, and some prototyping to complete the selection process

• Look for new concepts during the process

Documenting the selection process is nearly as important as the result

(and must be included in your design report)


Product Concept Selection Process

• Start with a Product Design Specification (PDS) that is finalized and has full team buy-in

• Examine ALL concepts at the same time


Concept Selection - Pictorially

Exhibit 7-4 “Product Design and Development” By Ulrich and Eppinger


Concept Selection Methods

• 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

• Intuition – The concept “feels” good. Explicit criteria and trade-

offs are not used. The concept just seems better.

Not recommended for this course



• Multi-voting – Each team member votes for several concepts. The

concept with the most votes is selected.

• Pros and cons – The team lists the strengths and weaknesses of each

concepts. The group then selects the best concept based on group opinion.

In this course, multi-voting is sometimes used in the screening process



• Prototype and test – Prototypes of each concept are built and tested and

the selection is made based upon the test data

• Decision matrices – The team rates each concept against pre-specified

selection criteria which are generally weighted – A required method for this course


Benefits of a Structured Method for Concept Selection

• A customer-focused product • A competitive design • Better product-process coordination • Reduced time to product introduction • Effective group decision making • Documentation of the decision process


2 Stages of Concept Selection

1. Concept screening • Reduce the many product concept ideas

generated to a relative few that will get additional refinement and analysis

2. Concept scoring • Use objective methods to select to your

consensus final concept selection


Concept Screening

1. Prepare the selection/screening matrix – Selection criteria must relate to key customer needs

2. Rate the concepts – e.g., + = “better than”, 0 = “same as”, - = “worse than”

3. Rank the concepts – As objectively as possible using the concept rating


Concept Screening

4. Combine and improve the concepts – Is there a generally good concept that is downgraded by

one feature? – Can two concepts be combined to preserve the “better

than” features while simultaneously removing any “worse than” features?

5. Select one or more concepts for further refinement and analysis

6. Reflect on the results and process – Are all team members “comfortable” with the decisions?

If not, what needs to be resolved?


Concept Screening Matrix Example



Concept Scoring

1. Prepare the selection matrix – An optimized version of the concept screening matrix – Determine % weighting for each selection criteria

2. Rate the concepts

5 “Product Design and Development” By Ulrich and Eppinger


Concept Scoring

3. Rank the concepts

Page 136 “Product Design and Development” By Ulrich and Eppinger


Concept Scoring

4. Combine and improve the concepts 5. Select one or more concepts for further

refinement and analysis • Sensitivity analysis • Build and test prototypes

6. Reflect on the results and process • Down-select to the consensus final concept selection


Concept Scoring Example


Sensitivity analysis on criteria weighting may provide insight


Commons Pitfalls in Concept Selection

• Not doing it • Running with the first idea • Forgetting the customer • Selection chart criteria don't correspond to PDS • Letting an "experienced" designer make the choices • Going by gut feel • Letting a manager decide • Not buying into the process as a team • Ignoring cost


Congratulations!

• You are now ready to implement a design solution* that addresses the customer’s needs (PDS).

• Implementation includes, but is not limited to: – Design and analysis – Fabrication of prototype(s) – Testing – Optimization – Documenting the design and design process

IDENTIFY OPPORTUNITY

DEFINE PROBLEM

GENERATE CONCEPTS

GATHER INFORMATION IMPLEMENT SCREEN

CONCEPTS HANDOFF

* or solutions

product concept selection - u of m: department of mechanical

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