CED Assign

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Transcript of CED Assign

Answers Prepared by me.so pls refer book for full understanding..

Answer ALL Questions

PART A (10 2 = 20 Marks)1. Differentiate Serial Engineering from Concurrent Engineering.Sl:NoSerial EngineeringConcurrent Engineering

1Traditional Engineering approach also known as " Serial Engineering", towards development had been largely sequential in nature.CEapproach encourages teamwork and it harnesses the expertise from all the disciplines that are involved to work closely together in parallel right from the early stage of the product design and development stage.

2control of two parameterAttempt to control all three parameter (Good, Quick, Cheap)



2. Classify the three categories of Design standards. Performance

Test methods

Codes of practice 3. Define House of Quality. QFD is a planning and problem-solving tool that is finding growing acceptance for translating customer requirements into the engineering characteristics of a product.

Group decision-making activity

Graphical representation using a diagram called House of Quality

4. What are the essential elements of IPR? Patents



Trade secrets

5. Classify conceptual decomposition. Decomposition in the physical Domain

Functional Decomposition6. State the principle of prototyping.7. State the importance of Value Engineering. Lowering O & M costs

Improving quality management

Improving resource efficiecy

Simplifying procedures

Minimizing paperwork

Lowering staff costs

Increasing procedural efficiency

Optimizing construction expenditures

Developing value attitudes in staff

Competing more sucessfully in marketplace

8. Define Material Performance Index.

A Material Performance Index is a group of material properties which governs some aspect of the performance of a component. If the performance index is maximized it gives the best solution to the design requirement.

9. Differentiate between MTBF and MTTF.Sl.noMTBFMTTF

1.MTBF (mean time between failures) is the expected time between two successive failures of a system.MTTF (mean time to failure) is the expected time to failure of a


2.MTBF is a

key reliability metric for systems that can be repaired or restored. Non-repairable systems can fail only once Therefore, for a non-repairable system, MTTF is equivalent to the mean of

its failure time distribution. . Repairable systems can fail several times

3.MTBF can be calculated as the inverse of the failure rate for constant failure rate systems.For constant failure rate systems, MTTF is the inverse of the failure rate. If failure rate is in failures/million hours, MTTF = 1,000,000 / Failure Rate for components with exponential distributions

10. What is meant by Fractional Factorial Design? fractional factorial designs are experimental designs consisting of a carefully chosen subset (fraction) of the experimental runs of a full factorial design.

The subset is chosen so as to exploit the sparsity-of-effects principle using a fraction of the effort of a full factorial design in terms of experimental runs and resources.

Fractional designs are expressed using the notation lkp,

where l is the number of levels of each factor investigated,

k is the number of factors investigated, and

p describes the size of the fraction of the full factorial used.

A design with p such generators is a 1/(lp) fraction of the full factorial design.

A way to reduce a huge full factorial to something



Required time, resources

Complexity of set-up for experiments

Major use is in screening experiments where the knowledge of

basic effects is not well known

If 2k is very large, may need to run reduced experiment

PART B (5 16 = 80 Marks)

11. (a) (i) Explain the Morris Asimovs morphology of design with a block

diagram. (12)Morphology of design:

Detailed description of the complete design process

The design Process

Phase I. Conceptual Design

It requires the creativity,

Single best concept, feasibility study

Coordination among many functions in the business organizations

Identification of customer needs

Problem definition Problem Statement


Quality Function Deployment (QFD)

Product Design Specification (PDS) Gathering information Internet



Literature Conceptualization Brainstorming



Morphological Chart Concept selection Pugh Concept Selection

Decision Matrix Refinement of the PDS

Design reviewPhase II: Embodiment design or preliminary design

Strength ,material selection, size, shape and spatial compatibility Product architecture

Dividing overall design system into sub system or modules

Arrangement of Physical Elements to carry out Function

Configuration design of parts and components Preliminary Selection of Parts and Materials

Modeling and Sizing of Parts

Parts are made up of features like holes, ribs, splines and curves

To determine what features will be present &how those features are arranged in space

Parametric design: To establish the exact dimensions and tolerances Robust Design


Final Dimensions

Design for Manufacturability (DFM)

Phase III: Detail Design Complete engineering description of a tested and producible product

Form ,dimensions, tolerances, properties, materials and manufacturing process of each part

Engineering drawings &computer generated drawings-determine assembly drg,

Before the information passed on to manufacturing

Phase IV: Planning For Manufacture Process sheet established

List of manufacturing operations that must be performed on the component

It specifies the form and condition of material and tooling &production m/cs

Estimation of production cost of the component

Designing specialized tools and fixtures

Specify production plant to be used

Planning the work schedules & inventory control

Planning the quality assurance system

Establishing the standard time and labor cost for each operation

Establish the system of information flow

Phase V: Planning For Distribution Effective distribution to the consumer of the system

Marketing, advertising and news media techniques Shipping Package


Shelf Life

WarehousesPhase VI: Planning For Use User oriented design process

Ease of maintenance ,reliability, safety, aesthetic appeal ,economy of operation, duration of service

Phase VII: Planning For Retirement Of The Product Disposal of the product, end of its useful life

Green design-recycling of materials, remanufacture, Useful Life


Technical Obsolescence

Fashion or Taste

Environmental Issues

Industrial Ecology Green Design


Power Consumption(ii) State the characteristics of an environmentally responsible design.

(4) Easy to disassemble

Able to be recycled

Contains recycled materials

Uses identifiable and recyclable plastics

Reduces use of energy and natural materials in its manufacture

Manufactured without producing hazardous waste

Avoids use of hazardous materials

Reduces product chemical emissions

Reduces product energy consumptionOr

(b) Explain material cycle, product cycle and manufacturing process cycle

with neat sketches. (16)12. (a) (i) Explain the process of identifying customer requirements with

suitable example. (8) Define the Scope

Mission Statement

Gather Raw Data


Focus Groups


Interpret Raw Data

Need Statements

Organize the Needs


Establish Importance


Quantified Needs

Reflect on the Process

Continuous Improvement

Example: Screwdriver Project

Product Description A hand-held, power-assisted device for installing threaded fasteners

Key Business Goals

Product introduced in 4th Q of 2000

50% gross margin

10% share of cordless screwdriver market by 2004

Primary Market

Do-it-yourself consumer

Secondary Markets

Casual consumer

Light-duty professional



Power assisted

Nickel-metal-hydride rechargeable battery technology




Sales force

Service center


Legal department

The process:

1. Gather raw data from customers

2. Interpret raw data in terms of customer needs

3. Organize needs into a hierarchy (primary, secondary, etc.)

4. Establish relative importance of each need

5. Reflect on the results and the process

2. Gather raw data from customers

1. Interviews

2. Focus groups

3. Observing product in use

3. Interpret raw data in terms of customer needs

1. Express need as what, not how

2. Express the need as specifically as the raw data

3. Use positive, not negative, phrasing

4. Express the nee