THE DESIGN PROCESS, DECISION MAKING AND NEW PRODUCT DESIGN 3(continue..)

2.2 Economics of material

      The consideration of cost plays such an important role in the design decision process that we could easily spend as much time in studying the cost factor as in the study of the entire subject of design. Materials  and labor usually show an increasing cost from year to year. But the costs of processing the materials can be expected to exhibit a decreasing trend because of the use of automated machine tools and robots. The cost of manufacturing a single product will vary from city to city and from one plant to another because of overhead, labor, taxes and freight differentials and the inevitable slight manufacturing variation.

1)      Standard sizes: The use of standard sizes is a first principle of cost reduction. For eg, if we need 53 mm size, then it can be obtained by special order or by rolling or machining a standard size 60 mm size, but these approaches add cost to the product.

1)      Large tolerances: Tolerances, manufacturing processes and surface finish are interrelated and influence the producibility of the end product in many ways. Close tolerances may necessitate additional steps in processing and inspection or even render a part completely impractical to produce economically.

2)      Breakeven Points: Two or more design approaches are compared for cost which depend on a set of condition such as quantity of production, the speed of the assembly lines or some other condition. These the occurs a point corresponding to equal cost, which is called breakeven point.

From figure, if the desired production is greater than 50 parts, the automatic machine should be used.

1)      Cost Estimation: There are many ways of obtaining relation cost figures so that two or more designs can be roughly compared. For eg, we can compare the relative value of two automobiles by comparing the dollar cost per pound of weight. Another way to compare the cost of one design with another is simply to count the number of parts. The design having the smaller number of parts is likely to cost less.

       2.3  Evaluation method for Material Selection 

¨  The Need for Material Selection 

¨ Intuitive Methods in Material Selection 

¨ Basics of Systematic Material Selection 

¨ Connection to Design

¨ Function Specification 

The Need for Material Selection

Due to the development of the materials but also due to the appearance of new production methods. As a consequence of this rapid development many material types can be used for a given component.

Intuitive Methods in Material Selection

1. First best material

2.  Same material as for a similar part

3.  Problem solving material selection

4.  Searching material selection

     2.4  COST AND PERFORMANCE

Material selection is one of the important aspect in machine design. During the selection of the material following points must be taken into consideration:

1.      The properties (density, weight, stiffness etc) of material

2.      Reliability of material

3.      Performance

4.      Cost of material

5.      Availability

All these are interrelated. The interrelation between performance and cost is discussed here.

     

       One of the step in product analysis is Cost Estimation. Before manufacturing any product, the cost required is estimated. Along with different other cost ( designing cost, machining cost), the cost of material plays a vital role. Let us take an example:

Suppose we are going to design the frame of bicycle (bike). Now we have to select the material of frame. We may select:

n   Steel –

                    Strong, stiff, heavy, but cheap

n  Aluminium –

                     Weaker, lighter, more expensive than steel

n  Composite (CFRP) –

                      Strong, stiff, very light, but expensive to buy and to fabricate

We can select steel frame as it is cheap. BUT what about the performance??? The bicycle (bike) may be : (a) racing bike (b) mountain bike (c) child bike. Now comes the relation between cost and performance. If we are going to manufacture a racing bike, then it should be light and stiff as speed and robustness is the main concern for racing bikes. In this case though it is cheap, we cannot select steel because it affect the performance of the bike. We should go to composite though its expensive. Now for child bike, we can go for aluminium.

   The cost and performance relations is usually analysed  with the help of Ashby Chart. It is a scatter plot which displays two or more properties (i.e. performance indices) of many materials or classes of materials.  Important concept of today is “ cost per unit of function”.  For example, if the key design objective is the stiffness of a plate of the material then the designer would need a material with the optimal combination of density, Young's modulus and price. So designer should always consider performance and cost simultaneously.

2.5 Cost and value analysis:

The consideration of cost plays very important role in design decision process that we could easily spend as much time in studying the cost in the study of the entire object design.Cost analysis is simply part of good program budgeting and accounting practices, which allow managers to determine the true cost of providing a given unit of service. Nothing can be said in absolute sense concerning costs. Material and labor usually show an increasing cost from year to year. But cost of production exhibit a decreasing trend because of the use of automated machine tools and robots. The cost of manufacturing a single product will vary from city to city and from one plant to another because over-head, labor, taxes and fright differentials and inevitable slight manufacturing and production.

Any two or more design processes can be compared in terms of costs by using break even analysis. The point corresponding to equal costs is the breakeven point. The region below the breakeven point is the region of loss and region above the breakeven point is the region of profit.

Fig: Break even analysis

Above figure shows that certain parts can be manufactured in two types of machines: Hand screw machine and Automatic screw machine. The breakeven point for two types of machine is 50 parts. If parts to be produced are greater than 50, it is cheaper to use automatic screw machine and if parts to be produced is less than 50 it is cheaper to use hand screw machine.

Value analysis can be defined as a process of systematic review that is applied to existing product designs in order to compare the function of the product required by a customer to meet their requirements at the lowest cost constituent with the specified performance and reliability needed. The key focus of value analysis is the management of ‘functionality’ to yield value for the customer.Value analysis can be used as a logical means of cost reduction. It is used to eliminate the lack of proper design review. It helps to be familiar with recent technology and customary practice, the advent of E-commerce, reducing complexity, implementing new technology and materials.

3. New Product Design

Product design is the process of creating a new product. It is essentially the efficient and effective generation and development of ideas through a process that leads to new products.

There are various product design processes and many focuses on different aspects. The process focuses on figuring out what is required, brainstorming possible ideas, creating mock prototypes, and then generating the product. However, that is not the end of the process. At this point, product designers would still need to execute the idea, making it into an actual product and then evaluate its success by seeing if any improvements are necessary.

The design process follows a guideline involving three main sections:

·         Analysis

·         Concept

·         Synthesis

Analysis

·         Accept Situation: Here, the designers decide on committing to the project and finding a solution to the problem. They pool their resources into figuring out how to solve the task most efficiently.

·         Analyse: In this stage, everyone in the team begins research. They gather general and specific materials which will help to figure out how their problem might be solved. This can range from statistics, questionnaires, and articles, among many other sources.

Concept

·         Define: This is where the key issue of the matter is defined. The conditions of the problem become objectives, and restraints on the situation become the parameters within which the new design must be constructed.

Synthesis

·         Ideate: The designers here brainstorm different ideas, solutions for their design problem. The ideal brainstorming session does not involve any bias or judgment, but instead builds on original ideas.

·         Select: By now, the designers have narrowed down their ideas to a select few, which can be guaranteed successes and from there they can outline their plan to make the product.

·         Implement: This is where the prototypes are built, the plan outlined in the previous step is realized and the product starts to become an actual object.

Evaluate: In the last stage, the product is tested, and from there, improvements are made. Although this is the last stage, it does not mean that the process is over. The finished prototype may not work as well as hoped so new ideas need to be brainstormed.

3.1 Feasibility studies:

Feasibility study is systemic procedure to find out the potential of any project or work going to carried out. This include the various stage upon which the study can be divided so that it can be understandable for reader and the person who is going to take decision based upon the finding and recommendation of feasibility study.

TABLE OF CONTENTS

1. EXECUTIVE SUMMARY

2. DESCRIPTION OF PRODUCTS AND SERVICES

3. TECHNOLOGY CONSIDERATIONS

4. PRODUCT/SERVICE MARKETPLACE

5. MARKETING STRATEGY

6. ORGANIZATION AND STAFFING

7. SCHEDULE

8. FINANCIAL PROJECTIONS

9. FINDINGS AND RECOMMENDATIONS

1. EXECUTIVE SUMMARY

The executive summary provides an overview of the content contained in the feasibility study document. Many people write this section after the rest of the document is completed. This section is important in that it provides a higher level summary of the detail contained within the rest of the document.

2. DESCRIPTION OF PRODUCTS AND SERVICES

This section provides a high level description of the products and/or services which are being considered as past of the feasibility study. The purpose of this section is to provide detailed descriptions of exactly what the organization is considering so this information can be applied to the following sections of the document. It is important that this description captures the most important aspects of the products and/or services that the organization is considering as well as how it may benefit customers and the organization.

3. TECHNOLOGY CONSIDERATIONS

This section should explain any considerations the organization must make with regards to technology. Many new initiatives rely on technology to manage or monitor various business functions. New technology may be developed internally or contracted through a service provider and always result in costs which must be weighed in determining the path forward.

4. PRODUCT/SERVICE MARKETPLACE

This section describes the existing marketplace for the products and/or services the organization is considering. It may describe who the target market consists of for these products or services, who the competitors are, how products will be distributed, and why customers might choose to buy our products/services. Most marketplaces are dynamic environments in which things change constantly. To enter a new marketplace blindly will usually result in an organization not fully understanding its role and not maximizing its resulting benefits.

5. MARKETING STRATEGY

This section provides a high level description of how the organization will market its product or service. Some topics which should be included are: how does an organization differentiate itself from its competitors; types of marketing the organization will utilize; and who the organization will target. Marketing efforts must be focused on the right target groups in order to yield the greatest return on investment.

6. ORGANIZATION AND STAFFING

With many new products or services there may be a need for additional staffing or for an organization to restructure in order to accommodate the change. These are important considerations as they may result in increased costs or require an organization to change its practices and processes.

7. SCHEDULE

This section is intended to provide a high level framework for implementation of the product or service being considered. This section is not intended to include a detailed schedule as this would be developed during project planning should this initiative be approved. This section may include some targeted milestones and timeframes for completion as a guideline only.

8. FINANCIAL PROJECTIONS

This section provides a description of the financial projections the new initiative is expected to yield versus additional costs. Financial projections are one key aspect of new project selection criteria. There are many ways to present these projections. Net present value (NPV), cost-benefit calculations, and balance sheets are just some examples of how financial projections may be illustrated. This section should also provide the assumptions on which the illustrated financial projections are based.

9. FINDINGS AND RECOMMENDATIONS

This section should summarize the findings of the feasibility study and explain why this course of action is or is not recommended. This section may include a description of pros and cons for the initiative being considered. This section should be brief since most of the detail is included elsewhere in the document. Additionally, it should capture the likelihood of success for the business idea being studied.

 3.2 Preliminary Design

After the detail study of the feasibility and application of the product, preliminary design is carried out. It is very important phase in the whole process of design and fabrication of products. The preliminary design is for the fulfillment of the design considerations. The design of the prototype is done and its performance and strength is tested whose data collection will help in further detail design. It is easier and economically helpful to test the prototype rather than the actual product and can be tested under various conditions also. The geometry, dimensions, surface profiles etc. are designed and taken into considerations. The design considerations are referred to some characteristics that influences the design of the system of the elements or the whole system. The factor of safety, strength, weight, size, thermal property, styling, shape are some of the specification that should be met. As preliminary design is just to assist the detail design it is not that important that the designed product will meet all the required specifications at first, they are tested and detail design will help meet those specifications. The design of the product should be carried out considering the facilities and potentiality of the plants and machine also. Both analysis optimization require that we construct or device abstract models of the system that will admit some form of mathematical analysis.

There are various computational tools for preliminary design, one of the most popular is CAD i.e. Computer Aided Design which facilitates editing and adding features which saves more time than paper design and drafting. There are other computer softwares which will simulate the design product in different operating conditions.

3.3.Detailed Design and Analysis

This stage in the design of a new product includes two aspects, that of design and of its analysis. This is the final stage in the design process, after which the manufacture of the product can be planned. Thus, all necessary calculations are done, all necessary charts are drawn and the problem is analysed from every possible angle.

Detailed design has to be obviously based on the preliminary design. As the name suggests, details need to be added to the rough preliminary design. The details have to be added keeping three points in mind: /adherence to specifications, producibility and the robustness required of the product/. The designer should obviously base his dimensions and tolerances, as well as the material and strength of his design, upon the specifications derived from the initial problem. Producibility is the character of the product which makes it possible for economic and timely manufacture. The robustness of the product, which decides the duration of product use must be based upon the specifications and limits of safety. As in all operations of design, the emphasis is on maximum efficiency and low cost of manufacture.

In some cases, after rigorous analysis of the design, the preliminary design may have to be completely disregarded. In such cases, the repetition of the design process or an alternate statement of the problem may be required.

The analysis of the design is done both in a mathematical and a pragmatic point of view. The simulation of real life application of the product, possible now with the help of /Computer Aided Design/, is an important tool used by modern designers. It allows them to test their design under strikingly real-life operating conditions, thus making it easier to detect flaws in the design.

After the analysis and after all possible corrections and enhancements have been made, the design process ends with the creation of the final blueprint or the final three-dimensional model of the product, which can be considered for manufactur

Compiled by:

Name  :        Pradip Pantha