THE DESIGN PROCESS, DECISION MAKING AND NEW PRODUCT DESIGN

Design Process (Introduction)

Engineering Design has been defined as the process of applying various techniques and scientific principles for the purpose of defining a device, a process or a system in sufficient detail to permit its realization. 
The engineering design process is a multi-step process including the research, conceptualization, feasibility assessment, establishing design requirements, preliminary design, detailed design, production planning and tool design, and finally production.” Essence of Engineering is design”.esign process includes following parts:

1.     Identification of need

2.     Background Research

3.     Goal Statement

4.     Performance Specifications

5.     Ideation and Invention

6.     Analysis and Selection

7.     Detail Design

8.     Prototyping and testing

9.     Production

1.      Identification of need

 The needs may come from the following sources

·         The necessity to make a product better or more profitable is a need

·         The establishment of a new product line to satisfy customers is a need

·         Protection of public health and safety is a need

·         An invention that is unexpected and is to be commercialized

·         An opportunity created by new technology, materials and scientific advances

·         A change in rules and regulations.

2.      Background Research

A significant amount of time is spent on research, or locating, information.  Consideration should be given to the existing applicable literature, problems and successes associated with existing solutions, costs, and marketplace needs.

The source of information should be relevant, including existing solutions. Reverse engineering can be an effective technique if other solutions are available on the market.  Other sources of information include the Internet, local libraries, available government documents, personal organizations, trade journals, vendor catalogs and individual experts available.

3.      Goal statement

The goal of this activity is to create a statement that describes what has to be accomplished to satisfy the needs of the customer. This involves analysis of competitive products, the establishment of target specifications, and the listing of constraints and trade-offs. Quality function deployment (QFD) is a valuable tool for linking customer needs with design requirements. A detailed listing of the product requirements is called a product design specification (PDS). Problem definition, in its full scope.

4.      Performance Specifications

The ‘specification’ is probably the easiest part of the design process. It is usually a list of points, with each point referring to the research work. In the specification you need to show what you have learnt from the research that you collected and presented in the research section.

A simple way of seeing if you have created a good specification  is to check whether key factors are covered. These may not all be appropriate to any one problem, but having checked them at least we will know the point has been considered. For example:

Size Function Appearance Storage Cost  Safety Environment Materials Shape Ergonomics Reliability Finish Maintenance                      

Other Factors

5.      Ideation and Invention

Concept generation involves creating a broad set of concepts that potentially satisfy the goal statement. Team-based creativity methods, combined with efficient information gathering, are the key activities.

Brainstorming is the most common technique for concept generation. The objective of brainstorming is to develop as many ideas as possible in a limited amount of time. Emphasis is on quantity rather than quality.

Free expression is essential in a brainstorming session. Evaluation of the ideas can be implemented in later time. Sometimes impractical ideas can inspire more viable ideas. To ensure a good design, multiple concept alternatives need to be generated.

 The following list can serve as a guideline for brainstorming:

·         No holding back: any idea may be brought to the floor at any time.

·         No boundaries: an idea is never too outrageous or “way out” to mention.

·         No criticizing. An idea may not be criticized until the final discussion phase.

·         No dismissing. An idea may not be discounted until after group discussion.

·         No limit. Another idea is never one too many.

·         No restriction. Participants may generate ideas from any field of expertise.

·         No shame. A team participant should never be made to feel embarrassed for contributing an idea.

Strategies to Enhance Creativity:

In generating ideas, the following strategies and techniques can enhance creativity.

o   Lateral thinking

o   Question

o   Practice

o   Suspend judgment

o   Allow time

o   Think like a beginner

o   Substitute

o   Combine

o   Adapt

o   Modify

o   Put to other use

o   Eliminate

o   Rearrange or reverse

6.      Analysis and Selection

This process involves evaluating concepts with respect to customer and other criteria, comparing the relative strengths and weaknesses of the concepts, and selecting one or more concepts for further investigation, testing, or development.

There are unstructured and structured methods for concept evaluation. In unstructured methods, the evaluation and selection may be made by experts, your supervisors, clients based on personal experience and/or preference. Structured methods are more objective comparatively. Decision matrix is an important structured concept selection technique.

Concept selection can be roughly broke into two similar stages in application of decision matrix technique, namely concept screening and concept scoring.

Figure 1 Concept Screening

Figure 2 Concept Scoring

7.      Detail Design

In this phase the design is brought to the stage of a complete engineering description of a tested and producible product. Missing information is added on the arrangement, form, dimensions, tolerances, surface properties, materials, and manufacturing processes of each part. This results in a specification for each special-purpose part and for each standard part to be purchased from suppliers. In the detail design phase the following activities are completed and documents are prepared:

● Detailed engineering drawings suitable for manufacturing. Routinely these are computer-generated drawings, and they often include three-dimensional CAD models.

● Verification testing of prototypes is successfully completed and verification data is submitted. All critical-to-quality parameters are confirmed to be under control.

Usually the building and testing of several preproduction versions of the product will be accomplished.

● Assembly drawings and assembly instructions also will be completed. The bill of materials for all assemblies will be completed.

● A detailed product specification, updated with all the changes made since the conceptual design phase, will be prepared.

● Decisions on whether to make each part internally or to buy from an external supplier will be made.

● With the preceding information, a detailed cost estimate for the product will be carried out.

● Finally, detail design concludes with a design review before the decision is made to pass the design information on to manufacturing. 

8.      Prototyping and Testing

Testing and Refinement, is concerned with making and testing many preproduction versions of the product. The first (alpha) prototypes are usually made with production-intent parts . These are working models of the product made from parts with the same dimensions and using the same materials as the production version of the product but not necessarily made with the actual processes and tooling that will be used with the production version. This is done for speed in getting parts and to minimize

the cost of product development. The purpose of the alpha test is to determine whether the product will actually work as designed and whether it will satisfy the most important customer needs. The beta tests are made on products made from parts made by the actual production processes and tooling. They are extensively tested inhouse and by selected customers in their own use environments. The purpose of these tests is to satisfy any doubts about the performance and reliability of the product, and to make the necessary engineering changes before the product is released to the general market. Only in the case of a completely “botched design” would a product fail at this stage gate, but it might be delayed for a serious fi x that could delay the product launch. During Phase 4 the marketing people work on developing promotional materials for the product launch, and the manufacturing people fi ne-tune the fabrication and assembly processes and train the workforce that will make the product. Finally, the sales force puts the fi nishing touches on the sales plan.

9.      Production

The manufacturing operation begins to make and assemble the product using the intended production system. Most likely they will go through a learning curve as they work out any production yield and quality problems. Early products produced during ramp-up often are supplied to preferred customers and studied carefully to find any defects. Production usually increases gradually until full production is reached and the product is launched and made available for general distribution. For major products there will certainly be a public announcement, and often special advertising and customer inducements. Some 6 to 12 months after product launch there will be a final major review. The latest financial information on sales, costs, profits, development cost, and time to launch will be reviewed, but the main focus of the review is to determine what were the strengths and weaknesses of the product development process. The emphasis is on lessons learned so that the next product development team can do even better.

1.2 Basic steps in the Design and Synthesis Process:

Mechanical Design/Product Design Process:

Several Major Steps:

1.      Define project and its planning

2.      Identify customers (users) and their needs

3.      Evaluate existing similar products (benchmarking)

4.      Generate engineering specifications & target values

5.      Perform conceptual design (Functional Modeling Approach)

6.      Perform concept evaluations

7.      Develop product/prototype

8.      Evaluate product for performance and cost

Planning for the design project:

Before launching into a detailed design process for a product, at least three things needed to be planned out first.

1.      Identify types of Design Projects

- Minor variation of an existing product

- Improvement of existing product

- Development of a new product

(a) For a single or small run

(b) For mass production

2. Form a Design Teams

- Available members and resources

3. Develop a Project Plan

- Identify the Tasks

- State the Objectives for each Task

- Estimate the Resources (Personnel, Time, etc.) needed to Meet the Objectives

- Develop a Sequence for the Tasks

- Estimate the Product Development Costs

Understand the problem and Develop Engineering specifications:

Quality function deployment (QFD) -- technique to generate engineering specifications.

It is used to develop the House of Quality for the product.

Important

“What” needs to be designed first,

Then concern about “How” the design will look and work.With this approach, QFD sets the foundation for generating concepts.

Functional Decomposition & Concept Generation:

Important customer requirements are concerned with the functional performance desired in the product. These requirements become the basis for the concept generation techniques.

• Functional Decomposition is designed to refine the functional requirements,

• Concept Variant Generation helps in transforming the functions into concepts.

4 basic steps in applying the Functional Decomposition technique to generate design functions:

(1) Find the Overall Function That Needs to be accomplished

          - State the “most important” function.

(2) Create Sub function Descriptions

- Decompose the main function into sub functions (what needs to happen?).

- Include known flows (material, energy, info.).

- Note operating sequence.

(3) Put Sub function in Order

- To order the functions in step (2) to accomplish the overall function in step (1).

- The order must be logical and in time sequence.

- Redundant sub functions must be recombined.

(4) Refine Sub functions

           - To decompose the sub function structure as fine as possible.

- Until the function can be fulfilled by existing objects

Basic Methods of Generating Concepts:

1. Brainstorming as a source of ideas

2. Using the 6-3-5 Method

3. Use of Analogies in Design

4. Use of Extremes and Inverses

5. Finding ideas in Reference Books and Trade Journals, Patents, etc.

6. Using Experts to help generate concepts

Patent Searches Websites:

http://www.uspto.gov/patft/index.html

http://www.delphion.com/home

http://gb.espacenet.com/

Techniques for Concept Evaluation:

Evaluation Based on Feasibility Judgment

- three reactions

(a) not feasible (reason why)

(b) might work if something else happens (conditional)

(c) worth considering

- Based on “gut feeling” – a comparison made with prior design experience and design knowledge.

Design/Product Evaluation for performance and Cost:

• Evaluation for Design Robustness

The word “robust” in design usually refers to final products that are of high quality because  they are insensitive to manufacturing variation, operating temperature, wear, and other uncontrolled factors so that performance is maintained.

   • Evaluation for Design Reliability

   • Evaluation for Design Manufacturing

   • Evaluation for Design Assembly

1.2.1 RECOGNITION OF THE NEED:

Recognition of the need is the first basic step in design and synthesis process. The need for a new design can be generated from several sources, including the following:

• Client request:

In a design company, a client may submit a request for developingan artifact. It is often unlikely that the need will be expressed clearly. The clientmay know only the type of product that he or she wants. For example, “I need asafe ladder.”

• Modification of an existing design:

Often a client asks for a modification of anexisting artifact to make it simpler and easy to use. In addition, companies may wantto provide customers with new, easy-to-use products. For example, in a marketsearch you may notice many brand names for coffee makers and the differencesamong them, such as shape, material used, cost, or special features. As another example, is the design developments for paperclips.Each of these designs has its own advantages over the other clips. For example, theendless filament paperclip can be used from either side of the clip. One may arguethat the different designs are based on the human evolution of designs and birth of new ideas; however, the major driving force for the renovation of designs is to keepcompanies in business.

• Generation of a new product:

In all profit-oriented industries, the attention, talent, and abilities of management, engineering, production, inspection, advertising,marketing, sales, and servicing are focused on causing the product to return profitfor the company and in turn for company stockholders. Unfortunately, sooner orlater, every product is preempted by another or degenerates into profitless pricecompetition. For an industry to survive in today’s world, it must continue to grow;it cannot afford to remain static. This growth, throughout history, has been built onnew products. New products have a characteristic lifecycle pattern in sales volumeand profit margins. A product will peak out when it hassaturated the market and then begin to decline. It is obvious that an industry mustseek out and promote a flow of new product ideas.

1.2.2  DEFINITION OF THE PROBLEM:

       In this stage of the design process, the designer defines what must be done to resolve the

need(s). The definition is a general statement of the desired end product. Many of the dif-

ficulties encountered in design may be traced to poorly stated goals, or goals that were

hastily written and resulted in confusion or too much flexibility.

In almost all cases, the client request comes in a vague verbal statement such as, “I

need an aluminum can crusher.”  Designers must recognize that customer needs are

not the same as product specifications. Needs should be expressed in  functional

terms. Customers will offer solutions; designers must determine the real needs,

define the problem, and act accordingly. During the customer interview, the

designer must  listen carefully to what the customer has to say. The designer’s

function is to clarify the  client’s design requirements. An objective tree may be

constructed for clarification. 

1.2.3 Gathering required information and functional requirements

As information provides better solutions, Information is most important in any designing work. This phase of the design process will help you appreciate your development and allow you to review what others have done in solving the same problem. It will also help you identify the size of the need and whom you are competing with. Furthermore, it will show what is available on the market.

Information can be obtained either from direct sources or from indirect sources. Direct source includes involves obtaining information directly from the consumer, manufacturers, salespeople, and so forth. The information is collected by interviews and surveys. Indirect sources include public sources, such as patents, journal reports, government analysis, and newspapers.

Functional requirements are required in order to satisfy customer. Either the customer is unsatisfied with the existing product or demands a completely new product is the first thing we need to understand. For a new product, the discussion usually focuses on their wishes and desires in a particular market segment, what they would like to see introduced to improve their lives, or what current problems exist in the similar products on the market. It provides a guideline in designing process.

 1.2.4        Conceptualization

• 1. Definition

• 2. Dimensions

• 3. Indicators

• 4. Comparison of Concept, Dimension, and

Indicator

• 5. Example

Definition

• Conceptualization is the process of development and clarification of concepts.

• In other words, clarifying one's concepts with words and examples and arriving at precise

verbal definitions.

• The ability to invent or formulate an idea or concept. The conceptualization phase of a project occurs in the initial design activity when the scope of the project is drafted and a list of the desired design features and requirements is created.

•One of the most difficult aspects of research -- and one of the least discussed -- is how to develop the idea for the research project in the first place.

• e.g., what is meant by education?

• “Amount of knowledge and training acquired in school."

Another Example

• What do we mean by "social status?”

– Wealth (millionaire)

– Prestige (Harvard professor)

– Power (military general)

• These are called “dimensions” of social status.

Dimensions

• We classify different meanings into different groups. Such groups are called "dimensions."

• A concept may have more than one dimension (e.g., as in case of social status).

• At a practical level, we are usually more interested in dimensions than in concepts

(which are more abstract, vague).

  

Indicators

• When a dimension is not directly observable, we use indicators.

• For example, to measure power, we may use

– (1) number of people under your supervision

– (2) extent of your supervision (work‐related only, or sleep and food?)

– (3) your annual budget

– (4) amount of equipment under your control

Comparison of Concept, Dimension,

and Indicator

• In practice, the three terms are often interchangeable (e.g., gender, race).

• One difference is the level of abstraction:

Concept Dimension Indicator Highly abstract Abstract Concrete

• One concept may have multiple dimensions; and one dimension may have multiple

indicators

A Related term: Variables

• A variable is a statistical term, meaning a quantity that can take on different possible

values.

• Both dimension and indicator can be variables.•When a concept has only one dimension withone indicator, a concept is practically equivalent to a variable.

Compiled by:

Name  :        Pradip Pantha