Assignment 7.1 Decision Tree

7.1 Construct a simple personal decision tree (without probabilities) for whether to take an umbrella when you go to work on cloudy day.

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Assignment: Pugh Chart

What is it?
Pugh Analysis charts are similar to the pros vs. cons lists. These are used for evaluating multiple options against each other, in relation to a baseline option. The method was invented by Stuart Pugh, University of Strathclyde in Glasgow, Scotland as an approach for selecting concept alternatives.


Why is it important?
The time it takes a development team to analyze the scores and weighting factors is usually much shorter and cheaper compared to deploying the wrong solution to a project. Ranking the criteria further helps focus the team's efforts on the critical few.


When to use it?
Rather than simply listing the positive and negative aspects of each option, one by one, a matrix of the needs vs. concepts helps address multiple factors at the same time and gives the team a holistic view of the needs vs. alternatives at hand.


How to use it?
Step by step process:

1. Develop a set of criteria based on customer's wants and needs.
2. Enhance these criteria by including any item of functional nature.
3. Develop a group of design concepts that are aimed at satisfying the criteria.
4. Using a simple matrix - list criteria on the left and the concepts across the top. Use simple sketches to illustrate each of these concepts.
5. Select one of the concepts as a baseline.
6. Evaluate each concept against the datum for each of the criteria. Determine whether it is better (+), the same (0) or worse(-) than the baseline. Alternately, one could assign a -1, 0, +1 based on where each choice would stack up against a set of the agreed-to criteria. We could give each of these criterion a weight and get the composite score of the alternate*criterion to determine the better alternative.
7. Record the team's decisions on the matrix.
8. For each column, determine the total number of pluses, minuses and sames. Alternately, take the sum of the alternate score multiplied by weight of the criterion.
9. Work to improve those concepts that scored best by incorporating strong ideas from other concepts.
10. Continue the process of synthesizing concepts.

Hints
In the Pugh Analysis winners and losers will become visible at an early stage. The fact that one is forced to carry out a reflected evaluation of each parameter for each of the concepts is very important and is useful to prevent later surprises. Even though obvious losers (or winners) may be found at an early stage, the process requires a continuous elaboration to optimize the concepts.


A Pugh matrix example

Let's say we're deciding between four alternatives, A, B, C, D. We already have a system in place and want to know if one of these four systems would be better for us.

We decide what our criteria are. We pick the four most important, the ones that absolutely must be included. Let's call them 1,2,3 and 4. (These can be price, time, ease of production, man-hours, whatever is most important. In companies, for example, they may get the customer/client involved here to ensure their satisfaction with the end result).

Let's draw our Pugh matrix. We put the alternatives across the top, and we are going to assess these with respect to the criteria, which we draw in on the left.



Our baseline is the system we have in place at the moment, so we score this a nought against our criteria. Our diagram will look like this.

Now consider option A. In relation to criteria 1, do we consider that it is better, the same as, or worse than the baseline? If it's better we give it a +1, if it's the same we give it a 0, and if it's worse we give it a -1. Let's say it's +1.

In terms of criteria 2, it's the same as the baseline. For criteria 3 it's better, and for criteria 4 its worse.

Our chart now looks like this.



We assess each of the alternatives B, C and D in the same way, filling in all the blanks.



So now we know the number of pluses, the number of minuses and the total score for each alternative, allowing us to make a more rational or objective decision. In this case it's obviously D, with three pluses and no minuses.


Weighting

We can also give each criterion a weighting. For example, if our first criteria is a 2, and the second criteria is twice as important we give that a four. The third criteria is somewhere in between, so it's a three. And the last criteria is probably the most important so that it gets a five. (It was funny writing that!!)

Our chart now looks like this.





Criteria 1 has a weighting of two. So all the numbers to the right of it are multiplied by two. Criteria four has a weighting of 5, so it's results are multiplied by five, etc.

Our Pugh matrix example now looks like this:



In our case the end result is the same, but depending on the number of criteria and the variables, the weighting you use can cause very different end results.

A further variation

Instead of the three-point scale we have used here, it it possible to use a five-point scale. For example:

+2 - much better than
+1 - better than
0 - equal to
-1 - worse than
-2 - much worse than

This can even be a 7 point scale, but anything finer may just complicate things unnecessarily.

Other Example

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Assignment: Quality Function Deployment (QFD)

QUALITY FUNCTION DEPLOYMENT (QFD)

Introduction

Quality Function Deployment (QFD) was developed to bring this personal interface to modern manufacturing and business. In today's industrial society, where the growing distance between producers and users is a concern, QFD links the needs of the customer (end user) with design, development, engineering, manufacturing, and service functions.

QFD is:

1.    Understanding Customer Requirements

2.    Quality Systems Thinking + Psychology + Knowledge/Epistemology

3.    Maximizing Positive Quality That Adds Value

4.    Comprehensive Quality System for Customer Satisfaction

5.    Strategy to Stay Ahead of The Game

As a quality system that implements elements of Systems Thinking with elements of Psychology and Epistemology (knowledge), QFD provides a system of comprehensive development process for:

·         Understanding 'true' customer needs from the customer's perspective

·         What 'value' means to the customer, from the customer's perspective

·         Understanding how customers or end users become interested, choose, and are satisfied

·         Analyzing how do we know the needs of the customer

·         Deciding what features to include

·         Determining what level of performance to deliver

·         Intelligently linking the needs of the customer with design, development, engineering, manufacturing, and service functions

·         Intelligently linking Design for Six Sigma (DFSS) with the front end Voice of Customer analysis and the entire design system

Quality Function Deployment (QFD) is a structured approach to defining customer needs or requirements and translating them into specific plans to produce products to meet those needs. The "voice of the customer" is the term to describe these stated and unstated customer needs or requirements. The voice of the customer is captured in a variety of ways: direct discussion or interviews, surveys, focus groups, customer specifications, observation, warranty data, field reports, etc. This understanding of the customer needs is then summarized in a product planning matrix or "house of quality". These matrices are used to translate higher level "what's" or needs into lower level "how's" - product requirements or technical characteristics to satisfy these needs.

While the Quality Function Deployment matrices are a good communication tool at each step in the process, the matrices are the means and not the end. The real value is in the process of communicating and decision-making with QFD. QFD is oriented toward involving a team of people representing the various functional departments that have involvement in product development: Marketing, Design Engineering, Quality Assurance, Manufacturing/ Manufacturing Engineering, Test Engineering, Finance, Product Support, etc.

The 'Voice of Customer'

Customer voices are diverse. In consumer markets, there are a variety of different needs. Even within one buying unit, there are multiple customer voices (e.g., children versus parents). This applies to industrial and government markets as well. There are even multiple customer voices within a single organization: the voice of the procuring organization, the voice of the user, and the voice of the supporting or maintenance organization.

These diverse voices must be considered, reconciled and balanced to develop a truly successful product. One technique to accomplish this is to use multiple columns for different priority ratings associated with each customer voice in the product planning matrix.

Quality Function Deployment requires that the basic customer needs are identified. Frequently, customers will try to express their needs in terms of "how" the need can be satisfied and not in terms of "what" the need is. This limits consideration of development alternatives. Development and marketing personnel should ask "why" until they truly understand what the root need is. Break down general requirements into more specific requirements by probing what is needed.

Once customer needs are gathered, they then have to be organized. The mass of interview notes, requirements documents, market research, and customer data needs to be distilled into a handful of statements that express key customer needs. Affinity diagramming is a useful tool to assist with this effort. Brief statements which capture key customer requirements are transcribed onto cards. A data dictionary which describes these statements of need are prepared to avoid any misinterpretation. These cards are organized into logical groupings or related needs. This will make it easier to identify any redundancy and serves as a basis for organizing the customer needs for the first QFD matrix.

QFD Methodoly Flow

Product Planning Using QFD

Once customer needs are identified, preparation of the product planning matrix or "house of quality" can begin. The sequence of preparing the product planning matrix is as follows:

1. Customer needs or requirements are stated on the left side of the matrix as shown below.

These are organized by category based on the affinity diagrams. Insure the customer needs or requirements reflect the desired market segment(s). Address the unspoken needs (assumed and excitement capabilities). If the number of needs or requirements exceeds twenty to thirty items, decompose the matrix into smaller modules or subsystems to reduce the number of requirements in a matrix. For each need or requirement, state the customer priorities using a 1 to 5 rating. Use ranking techniques and paired comparisons to develop priorities.

2. Evaluate prior generation products against competitive products. Use surveys, customer meetings or focus groups/clinics to obtain feedback. Include competitor's customers to get a balanced perspective. Identify price points and market segments for products under evaluation. Identify warranty, service, reliability, and customer complaint problems to identify areas of improvement. Based on this, develop a product strategy. Consider the current strengths and weaknesses relative to the competition? How do these strengths and weaknesses compare to the customer priorities? Where does the gap need to be closed and how can this be done - copying the competition or using a new approach or technology? Identify opportunities for breakthrough's to exceed competitor's capabilities, areas for improvement to equal competitors’ capabilities, and areas where no improvement will be made. This strategy is important to focus development efforts where they will have the greatest payoff.

3. Establish product requirements or technical characteristics to respond to customer requirements and organize into related categories. Characteristics should be meaningful, measurable, and global. Characteristics should be stated in a way to avoid implying a particular technical solution so as not to constrain designers.

4. Develop relationships between customer requirements and product requirements or technical characteristics. Use symbols for strong, medium and weak relationships. Be sparing with the strong relationship symbol. Have all customer needs or requirement been addressed? Are there product requirements or technical characteristics stated that don't relate to customer needs?

5. Develop a technical evaluation of prior generation products and competitive products. Get access to competitive products to perform product or technical benchmarking. Perform this evaluation based on the defined product requirements or technical characteristics. Obtain other relevant data such as warranty or service repair occurrences and costs and consider this data in the technical evaluation.

6. Develop preliminary target values for product requirements or technical characteristics.

7. Determine potential positive and negative interactions between product requirements or technical characteristics using symbols for strong or medium, positive or negative relationships. Too many positive interactions suggest potential redundancy in "the critical few" product requirements or technical characteristics. Focus on negative interactions - consider product concepts or technology to overcome these potential tradeoff's or consider the tradeoff's in establishing target values.

8. Calculate importance ratings. Assign a weighting factor to relationship symbols (9-3-1, 4-2-1, or 5-3-1). Multiply the customer importance rating by the weighting factor in each box of the matrix and add the resulting products in each column.

9. Develop a difficulty rating (1 to 5 point scale, five being very difficult and risky) for each product requirement or technical characteristic. Consider technology maturity, personnel technical qualifications, business risk, manufacturing capability, supplier/subcontractor capability, cost, and schedule. Avoid too many difficult/high risk items as this will likely delay development and exceed budgets. Assess whether the difficult items can be accomplished within the project budget and schedule.

10. Analyze the matrix and finalize the product development strategy and product plans. Determine required actions and areas of focus. Finalize target values. Are target values properly set to reflect appropriate trade off? Do target values need to be adjusted considering the difficulty rating? Are they realistic with respect to the price points, available technology, and the difficulty rating? Are they reasonable with respect to the importance ratings? Determine items for further QFD deployment. To maintain focus on "the critical few", less significant items may be ignored with the subsequent QFD matrices. Maintain the product planning matrix as customer requirements or conditions change.

QFD Process

Quality Function Deployment begins with product planning; continues with product design and process design; and finishes with process control, quality control, testing, equipment maintenance, and training. As a result, this process requires multiple functional disciplines to adequately address this range of activities. QFD is synergistic with multi-function product development teams. It can provide a structured process for these teams to begin communicating, making decisions and planning the product. It is a useful methodology, along with product
development teams, to support a concurrent engineering or integrated product development approach .

Quality Function Deployment, by its very structure and planning approach, requires that more time be spent up-front in the development process making sure that the team determines, understands and agrees with what needs to be done before plunging into design activities. As a result, less time will be spent downstream because of differences of opinion over design issues or redesign because the product was not on target. It leads to consensus decisions, greater commitment to the development effort, better coordination, and reduced time over the course of
the development effort.

QFD requires discipline. It is not necessarily easy to get started with. The following is a list of recommendations to facilitate initially using QFD.

• Obtain management commitment to use QFD.
• Establish clear objectives and scope of QFD use. Avoid first using it on a large, complex project if possible. Will it be used for the overall product or applied to a subsystem, module, assembly or critical part? Will the complete QFD methodology be used or will only the product planning matrix be completed?
• Establish multi-functional team. Get an adequate time commitment from team members.
• Obtain QFD training with practical hands-on exercises to learn the methodology and use a facilitator to guide the initial efforts.
• Schedule regular meetings to maintain focus and avoid the crush of the development schedule overshadowing effective planning and decision-making.
• Avoid gathering perfect data. Many times significant customer insights and data exist within the organization, but they are in the form of hidden knowledge - not communicated to people with the need for this information. On the other hand, it may be necessary to spend additional time gathering the voice of the customer before beginning QFD. Avoid technical arrogance and the belief that company personnel know more than the customer.

Quality Function Deployment is an extremely useful methodology to facilitate communication, planning, and decision-making within a product development team. It is not a paperwork exercise or additional documentation that must be completed in order to proceed to the next development
milestone. It not only brings the new product closer to the intended target, but reduces development cycle time and cost in the process.

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Morphological Chart and Concept Generation

CONCEPTUAL DESIGN TECHNIQUES

1) Needs and Goals

  – Need statement

  – Objectives tree

  – Functional analysis

2) Concept Development

  – Brainstorming

  – Morphological chart 

3) Concept Evaluation

  – Sketch concepts

  – Evaluation Matrices

     A morphological chart is a table based on the function analysis. On the left side of the chart the functions are listed, while on the right side, different mechanisms which can be used to perform the functions listed are drawn. It is a visual aid used to come up with different ideas. The idea generation is accomplished by creating single systems from different mechanisms illustrated in the morphological chart.  It is advised to generate several feasible designs using different mechanisms for each function for each concept.

BENEFITS

• Allows visualization of design space

– Gives us a sense of size

– Allows us to identify potential designs

– Allows us to identify and exclude incompatible 

   alternatives

HOW TO CREATE?

• Make list of features we want the design to have 

or functions we want it to perform

– Should be manageable size

– All features/functions at similar level of detail

• Build a list of means of achieving each function 

and create a table

• Choose one means from each row to combine 

into a design

• Number of possible designs = (#entries row 1) x 

(#entries row 2) x (#entries row 3) x ...

– Not all are feasible

     Figure 1 depicts a morphological chart for a vegetable collection system, continued from the Lateral Thinking Model above. See how the Generated Alternatives from before have now been formed into a matrix with images to help explain further. These sketches don’t have to be Monet, but they do need to clearly describe the product. You would then pick a path through them to begin design Concept number 1, as Figure 2 suggests.

Figure 1: Morphological chart for a vegetable collection system

Figure 2 - Morphological Analysis for vegetable collection system with selections (Haik and Shahin 2011: 175)

You are NOW at a stage to begin concept design.

Your first few concept designs should follow different routes through the Morphological Matrix, that is why you have compiled it. Do not ignore it. In this instance;

Concept 1 could be – scoop > conveyor belt > water from well > bowl > track system > wind blown
Concept 2 could be – triangular plow > rotating mover > water from well > wheel > hand push
Concept 3 could be - scoop > conveyor belt > square mesh > wheel > hand push

     Once you begin to combine these ideas, you’ll gain momentum and start to generate lots of ideas, organise your thoughts, change, erase, scrap, retrieve from bin, enthuse, destroy and generally go through the generation process. The image below is a very good example of how you might sketch a number of alternatives to investigate different concepts.

ALWAYS ANNOTATE YOUR SKETCHES. It makes it easier for you to describe the process.

     It’s generally accepted that you should produce at least three well-considered concepts, annotated and developed to a level that is distinguishable as an acceptable solution. The diagram in Figure 3 represents how your ideas may begin to narrow as you develop your ideas.

Figure 3: Flexible design model (Pugh 1991: 75)

NEXT STEP

     The concepts arrived upon using the morphological chart are then screened against each other and against the customer needs. Always keep in mind the PDS and QFD you formed and constantly check back to ensure you’re keeping with the guidelines. You will decide upon a Final Concept using Pugh’s Matrix at the next step.   This is done as a preliminary decision matrix (Evaluation matrices) to see which concepts are going to be further analyzed.

“An idea is nothing more nor less than a new combination of old elements.” (Foster 2007: 13).

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