ENGINEERING DESIGN 1

Ir Dr Zainal Fitri B Zainal Abidin

Sept 2014

Topic 5 :Design for Manufacturing

CONTENT

Introduction Definition to design for manufacturing Estimation of manufacturing costs Reduction of cost in components, assembly

and supporting production The impact of DFM on other factors

DESIGN FOR MANUFACTURING - INTRODUCTION

Basically manufacturing activities are divided into following functions : Process engineering

Rate of Production Cost of manufacturing component

Tool engineering Design Of Tools Jigs, Fixtures & Gauges to produce parts

Work standards Time to cost for produce product

Plant engineering Providing plant facilities (space, transportation, storage etc)

Administration & control

Production Planning Scheduling Manpower Supervising

DESIGN FOR MANUFACTURING - INTRODUCTION

Modern manufacturing system now uses Computer Integrated Manufacturing ( CIM) to efficiency

DESIGN FOR MANUFACTURING - INTRODUCTION

Modern manufacturing system now uses Computer Integrated Manufacturing ( CIM) to efficiency

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Casting Process

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Polymer (Molding) Process

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Deformation Process

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Powder Processing

Gypsum Factory

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Metal removal or cutting (Machining) Processes

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Joining Processing

Brazing Adhesive

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Heat Treatment & surface Treatment

Heat Treatment using Furnace Surface Treatment using laser

DESIGN FOR MANUFACTURING - INTRODUCTION

Classes Of Manufacturing Process : Assembly Process

DESIGN FOR MANUFACTURING - INTRODUCTION

Types Of Manufacturing System : Job Shop

DESIGN FOR MANUFACTURING INTRODUCTION

Types Of Manufacturing System : Batch Flow

Batch Flow for sealant production

DESIGN FOR MANUFACTURING INTRODUCTION

Types Of Manufacturing System : Assembly Line

DESIGN FOR MANUFACTURING INTRODUCTION

Types Of Manufacturing System : Continuous Flow

CONTENT

Introduction Definition to design for manufacturing Estimation of manufacturing costs Reduction of cost in components, assembly

and supporting production The impact of DFM on other factors

DESIGN FOR MANUFACTURING DEFINITION DFM

DEFINITION

Design for manufacturing (DFM) is the material

and tooling cost issues throughout the product

development process.

Successful DFM results in lower production cost

without sacrificing product quality.

DESIGN FOR MANUFACTURING DEFINITION DFM

Estimate the manufacturing costs

Reduce the costs of the components

Reduce the costs of the assembly

Reduce the costs of the supporting production

Consider the impact of DFM on other factors

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 1. Minimise total number of parts

Eliminate parts means great savings. Parts eliminated cost nothing to make, assemble, store or service

The best way to eliminate parts is to make minimum part count a requirement of the design

Combining two or more parts into one is another approach

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 2. Standardize Components

- Cost are minimized and quality is enhanced when standard commercially available components are used in the design

- Standardized parts will gives cost reduction through quantity discounts, elimination of design effort, avoidance of equipment and tooling costs and better inventory control

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 3. Use common parts across product lines

- Specify same material, parts and sub assemblies in each product as much as possible. It provides economic of scales and easy operator training and control.

- PDM (product data management) systems can be use to facilitate similar design

4. Standardise Design Features -Standardizing on design features (eg drilled holed sizes etc) will minimizes usage the number of tools hence reduce manufacturing cost

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 5. Aim to keep designs functional and simple

- The simplest design will usually the most reliable and easiest to maintain.

- Do not specify more performance than is needed e.g using heat treated alloy steel when a plain carbon steel will achieve the required performance

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 6. Designs Parts to be multi functional

- A good way to minimize part count is to design such parts can fulfill more than one function leading to integral architecture.

+ + =

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 7. Designs Parts for easy fabrication

- Choose least costly material that satisfies functional requirement.

- In general material with higher strength have poor workability or fabricability.

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 8. Avoid excessively tight tolerances

- Tolerances must be set with great care. Specifying tighter tolerances will increase cost.

- Designer must maintain credibility with manufacturing with regard to tolerances.

9. Minimise Secondary and finishing Operations : -Minimise secondary operations such as heat treatment and try to avoid finishing operation such as deburring, plating, painting and polishing unless its necessary. Use it when there is a functional or aesthetic reason for doing so.

DESIGN FOR MANUFACTURING DEFINITION DFM

DFM Guidelines 10. Utilize the Special characteristics of processes

- Be alert to special design that many processes provide. - E.g Metal polymers can be provided with built in colour as

opposed to metal that need to be painted or plated.

DESIGN FOR MANUFACTURING DEFINITION DFM

DFA (Design for Assembly) General Guidelines 1. Minimize Total number of Parts

- Parts is not required by the design is a part that does need to assembled.

- Criteria for essential part : Part that exhibit motion relative to another part is declared essential There is a fundamental reason that the part is made from different material

from all other parts. Maintenance of the product may require disassembly and replacement of a

part Parts only used for fastening or connecting other parts are prime

candidates for elimination It would not be possible to assemble or disassemble the other parts unless

this part is separate, which is essential

DESIGN FOR MANUFACTURING DEFINITION DFM

DFA (Design for Assembly) General Guidelines 2. Minimize the Assembly surfaces

- Simplify design so that fewer surfaces need to be prepared in assembly and all work on one surface is completed before moving to the next one.

3. Use subassemblies : -Provides economies in assembly since there are fewer interfaces in final assembly -Product made from subassemblies are easier to repair by replacing the defective subassembly

4. Mistake proof the design and assembly: - Poka Yoke method

DESIGN FOR MANUFACTURING DEFINITION DFM

DFA (Design for Assembly) Handling Guidelines 5. Avoid separate fasteners or minimize fastener cost

- Cost of fastener maybe cheap but the labor of proper handling in assembly can reach 75% of the assembly cost.

- Use snap fit whenever is possible

6. Minimize handling in Assembly: - Parts should be designed to make the required position for insertion or joining easy to achieve.

DESIGN FOR MANUFACTURING DEFINITION DFM

DFA (Design for Assembly) Insertion Guidelines 7. Minimize assembly direction

- All products should be designed so that they can be assembled from one direction

8. Provide unobstructed access for parts and tools: - There must be adequate assembly path (space) for the part to be moved to this location.

9. Maximise Compliance in assembly: - Design in compliance to include allowance for excessive force on parts that are not identical.

DESIGN FOR MANUFACTURING DEFINITION DFM

Mistake Proofing (Poka Yoke) Japanese approach to 'mistake proofing' in all aspects of manufacturing, customer service, procurement, etc. It employs visual signals that make mistakes clearly stand out from the rest, or devices that stop an assembly line or process if a part or step is missed

DESIGN FOR MANUFACTURING DEFINITION DFM

Mistake Proofing (Poka Yoke) There are 4 categories of mistakes in part production. a) Design Mistakes b) Defectives Material mistakes c) Manufacturing mistakes d) Human Mistakes

DESIGN FOR MANUFACTURING POKA YOKE

a) Design Mistakes Mistakes attribute to the design process : Ambiguous information on engineering drawing or

specifications Failure to properly use dimension and tolerances.

Incorrect information. Mistakes in conversion units or wrong calculations

Poorly developed design concept that does not fully provide the need functionality. Hastily made design decision that results poor performing product with low reliability or with dangers to the safety of human or hazard for environment

DESIGN FOR MANUFACTURING POKA YOKE

b) Defective Material Mistakes Mistakes attributes : Material that is poorly chosen because not all performance

requirement have been considered in selection. Material that does not meet the specifications but goes into

production or purchased components that are not up to quality standards

Parts with hard to detect flaws such as internal porosity or fine surface crack due to poor die design or impropoer process

DESIGN FOR MANUFACTURING POKA YOKE

c) Manufacturing Mistakes Common mistakes in manufacturing parts : Omitted operations : failure to perform a required step in the

process plan. Omitted part : Forgetting to install a screw, gasket or washer Wrong orientation of parts: A part inserted in propoer location

but wrong orientation Misaligned part : Alignment not accurate to give proper fit Wrong location of part : Part is oriented properly but wrong

location. Selection of wrong parts : parts may look alike but different

sizes

DESIGN FOR MANUFACTURING POKA YOKE

c) Manufacturing Mistakes Common mistakes in manufacturing parts : Misadjustments : An operation is incorrectly adjusted Commit prohibited action : safety violation failure to lock out

a power panel before hooking up a motor Added material or parts : Failure to remove material. E.g

newspaper inside the fuel tank (used for painting protective) or extra parts (screw inside engine)

Misread, mismeasure or misinterpret : error in reading measurements, dimensions or understanding correct information.

DESIGN FOR MANUFACTURING POKA YOKE

c) Human Mistakes

Human Mistakes Safeguard

Inattentiveness Discipline; work standardization; work instructions

Forgetfulness Checking at regular intervals

Inexperience Skill enhancement; work standardization

Misunderstanding Training; checking in advance; standard work practices

Poor Identification Training; attentiveness; vigilance

CONTENT

Introduction Definition to design for manufacturing Estimation of manufacturing costs Reduction of cost in components, assembly

and supporting production The impact of DFM on other factors

DESIGN FOR MANUFACTURING ESTIMATION OF MANUFACTURING COST

Overview DFM Estimation Manufacturing Cost Method

DESIGN FOR MANUFACTURING ESTIMATION OF MANUFACTURING COST

Unit Manufacturing cost of a product consists of 3 cost categories : Component Cost Assembly Cost Overhead Cost

DESIGN FOR MANUFACTURING ESTIMATION OF MANUFACTURING COST

DESIGN FOR MANUFACTURING ESTIMATION OF MANUFACTURING COST

DESIGN FOR MANUFACTURING ESTIMATION OF MANUFACTURING COST

CONTENT

Introduction Definition to design for manufacturing Estimation of manufacturing costs Reduction of cost in components, assembly

and supporting production The impact of DFM on other factors

DESIGN FOR MANUFACTURING REDUCTION OF COST IN COMPONENTS, ASSEMBLY AND SUPPORTING PRODUCTION

UNDERSTANDING THE COST DRIVERS Fixed Cost Fixed costs are costs that are independent of output. These remain constant throughout the relevant range and are usually considered sunk for the relevant range (not relevant to output decisions). Fixed costs often include rent, buildings, machinery, etc Variable Cost Variable costs are costs that vary with output. Generally variable costs increase at a constant rate relative to labor and capital. Variable costs may include wages, utilities, materials used in production

DESIGN FOR MANUFACTURING REDUCTION OF COST IN COMPONENTS, ASSEMBLY AND SUPPORTING PRODUCTION

Variable Cost Cost Unit Cost Materials 5.7 kg aluminium

@$2.25/kg 12.83

Processing (casting) 150 unit/hr at $530/hr 3.53 Processing (Machining) 200 unit/hr at $340/hr 1.70 Fixed Cost Tooling For Casting $160,000 @500k units 0.32 Machine Tools & fixtures $1,800,000 @10M units 0.18 Total Direct Cost Overhead Charges $12.09

Total unit Cost $30.65

Cost Estimate For intake manifold

DESIGN FOR MANUFACTURING REDUCTION OF COST IN COMPONENTS, ASSEMBLY AND SUPPORTING PRODUCTION

Variable Cost Cost Unit Cost Materials 5.7 kg aluminium @$2.25/kg 12.83

Processing (casting) 150 unit/hr at $530/hr 3.53

Processing (Machining) 200 unit/hr at $340/hr 1.70

Fixed Cost

Tooling For Casting $160,000 @500k units 0.32

Machine Tools & fixtures $1,800,000 @10M units 0.18

Total Direct Cost

Overhead Charges $12.09

Total unit Cost $30.65

Question: How do you reduce the cost per unit?

CONTENT

Introduction Definition to design for manufacturing Estimation of manufacturing costs Reduction of cost in components, assembly

and supporting production The impact of DFM on other factors

DESIGN FOR MANUFACTURING IMPACT OF DFM ON OTHER FACTORS

The Impact of DFM on Development time Development time is precious, the delay of the project may impact income of several hundred thousand dollars per day. The Impact of DFM on Development cost Similar to development time. In general the product team will pursue low manufacturing cost with high quality product intend and meeting the target timing for product launch.

DESIGN FOR MANUFACTURING IMPACT OF DFM ON OTHER FACTORS

The Impact of DFM on Product Quality Evaluating the impact of the decision on quality is essential as many dimensions of quality are important for business sustainability. (In few cases reducing manufacturing cost may have an adverse effect on reliability and robustness) The Impact of DFM on External Factors Design decision that may impact responsibilities beyond single development team - Component reuse : taking time and money in creating low cost component

maybe a value to other team.

- Life cycle costs: Throughout the product lifecycles, it may incur some company or societal cost. i.e products that contain toxic waste material may require

special handling in disposal

THE END

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