13.sorting and screening the ideas 2

7/27/2019 13.Sorting and Screening the Ideas 2

1/22

Screening the Ideas


2/22

Introduction We have seen sorting of ideas, which reduced the number of concepts

for more quantitative consideration. For simple product designs, the idea sorting may suggest only one or

two strong ideascan then proceed directly to Selection stage.

In other cases, we have to go through screening process. We need a basis for qualitative judgments to further reduce the

selection. To compare different product ideas, we need a variety of criteria:

Purely objective questions: Which of these two absorbents has a greatercapacity? Which battery has greater power per mass?

More subjective criteria: Which of the two fabrics is more wearable?

Which of the products is safer? In more complex cases, we will be making compromises between two

conflicting criteria: how to decide between different home air purifierswhose performance and cost go up together?


3/22

Strategies for Idea Screening Clearly, many possible strategies for ideas screening.

Easiest approach: to look at the headings in theoutline, and choose the best candidate under each

heading. This strategy works well if the product designs are

simple extensions of existing technology.

A significant risk: two best ideas may be under the

same subheading. This strategy is very risky if there are many, very

different product designs.


4/22

Strategies for Idea Screening A more effective strategy is to determine factors by which to

evaluate the product: Scientific maturity. We prefer designs based on scientific

knowledge already understood.

Engineering ease. We prefer designs that imply straightforwardengineering akin to that used in established manufacturing. Minimum risk. We prefer not to take chances; would like to know

our chances of success. Low cost. We want a rough estimate of relative cost of our ideas. Safety. We prefer products which are inherently safer.

Low environmental impact. We prefer less pollution Other factors may be more subjective. E.g., the product should

be quiet or the product should be comfortable.

We need to choose five or fewer factors that are mostimportant. How? Concept screening matrix.


5/22

Concept-screening Matrix The choice of most important factors is best made by

consensus, with the entire core team working together. In seeking this consensus, the team members need to be

careful not to compete, not to feel that their chosen factors will

be winners or losers. Need to note that some individuals are rational and some

individuals can precipitate polarization and win-lose arguments. Once the key factors are identified, we assign (normalized)

weighting factors to them.

Experience shows that the core team reaches the consensus onweighting factors more quickly than on the choice of the factorsthemselves.

1

1

n

i

i

iis weighting factor for attribute i.


6/22

Concept-screening Matrix With these weighting factors in hand, the key ideas are

evaluated on basis of some scale.

Easiest scale ranges from a low score of one to a high score of

ten. To begin, we assign an average score of five to the benchmark.

Then each product idea is graded relative to this benchmark.

We thus have a group of scores sijfor each attribute i and eachidea j.

The total score for each idea is then:

The ideas with the highest scores are then used for the nextstage of product design: selection.

n

i

ijisjScore1

)(


7/22

Improving the Idea Screening

Process The simple procedure outlined above can be

improved:

First, a careful choice of the benchmark. In many cases, the benchmark will be an existing

product with the greatest market share.

Or it may be, a potential product from competitors.

Or it may be the best of the existing products.

As a check, try to choose a different benchmark after afirst round of assessments, just to make sure our firstbenchmark is best.


8/22

Improving the Idea Screening

Process Second, check the core teams scores against

those of other interested experts. One obvious group are other individuals in marketing

outside our core team. Another group are the lead users of current products.

Third, make a sensitivity analysis of the weightingfactors. Essentially, change the weighting factors within sensible

limits to see if this alters our rank ordering of the ideas. Usually, little change; if change is dramatic, re-examine

the selection criteria we may not have considered allmajor issues.


9/22

Improving the Idea Screeing

Process An important assumption made in the matrix

approach is that everything can be scored andweighted linearly.

This is approximately true only when the productsare similar, changed only in minor ways. The assumption of linearity is untrue if:

The criterion is binary. E.g., the product may be judgednoisy or quiet, with nothing in between.

The product will not work. E.g., the product may depend onmaking an invention which may not be possible.

The product changes the market. I.e., the product is sogood that all other criteria are irrelevant. The product is ashow stopper or game changer or step-out technology.


10/22

Example Home Oxygen

Supply Those with lung disorders, including

emphysema, can sometimes benefit frombreathing air enriched with oxygen.

This oxygen is presently supplied as cylindersof nearly pure oxygen, regularly delivered.

This can be expensive; shifting of cylindersaround the house can be difficult, especially if

the user is older. Need to find an alternative to gas cylinders to

provide home oxygen.


11/22

Example Home Oxygen

Supply Two reasonable alternatives: membrane separation and

pressure swing adsorption (PSA). The membrane separation uses selective hollow fibers in a

module like a shell and tube heat exchanger, but with tubes ~

1mm in diameter. It requires a pump to compress room air and force it across the

fibers. This permeate air will contain perhaps 30% oxygen.

The PSA unit uses an adsorbent, often a zeolite. The air at high pressure is forced through until the adsorbant is

saturated with O2. Then the flow is stopped and the pressure is released. The air coming out of the bed is enriched with O2. This system also requires a pump, as well as some valving.

Need to choose key factors and evaluate the two ideas.


12/22

Example Home Oxygen

Supply The core team decided that there are three key

factors: Convenience this is marginally more important factor.

Noise may be unimportant to a geriatric patient who isdeaf, but important to anyone who lives with the patient.

Cost Important if the patient pays; however if the costsare borne by insurance, not so important.

All three factors of roughly equal importance.

On this basis, we can prepare a concept-screeningmatrix.


13/22

Example Home Oxygen

Supply


14/22

Example Home Oxygen

Supply Convenience is given a slightly greater

importance than either noise or cost.

As benchmark, the gas cylinder is alwaysgiven score of 5.

The hollow fiber membranes have top score,followed by the PSA.

However, it may be harder to make amembrane with the desired properties thanto locate an effective zeolite adsorbent.


15/22

Example High Level

Radioactive Waste Cesium, 137Cs, is a radioactive by-product of atomic

weapons manufacture. Other by-products can be precipitated using basic

solution but not Cesium. Cesium remains dissolved in aqueous solutions. Millions of gallons of this aqueous solutions are

stored in tanks in the locations where atomicweapons are manufactured.

If tanks leak because of aging or earthquakes, theescaping cesium would spell disaster. How to make the cesium less dangerous? Several ideas have been suggested.


16/22

Example High LevelRadioactive Waste


17/22



18/22



19/22


Choice of benchmark existing process Precipitation of the cesium cation with the tetraphenylborate

anion.

Key factors chosen: Known science

Reliable engineering

Safety

Public response

Cost not a factor since all processes expected to be veryexpensive.

Each of the promising processes scored by usingthese criteria.


20/22



21/22

Conclusions

This chapter describes the generation and screening of ideas,the second step of product design.

We welcome product ideas from every possible source: Core team Customers, competitors and consultants Brainstorming

A useful target ~ 100 ideas. Then we organize the ideas, removing redundancy and pruning

folly. This gives ~ 20 candidates. We then use concept screening methods to evaluate further and

reduce the number to five or fewer. After the ideas are screened, we must select among the best

choices and manufacture the products. This comes next.


22/22

Second Management Review(The Second Gate)

Again the core team makes a presentation to the same seniormanagement group. This presentation will include both oral and written components.

The management will decide whether or not to continue the

work. The management team may be charmed by suggested

innovations and excited by product improvements. Management teams with nontechnical background may require

help in making reasoned decisions. The core team must, hence, be especially careful to be

objective. The team must make sure to highlight not only the potential

rewards, but also the risks. After this stage, product development gets more expensive.

13.sorting and screening the ideas 2

Documents