me 333 manufacturing processes-ii introduction to manufacturing & production lecturer(s): prof....
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ME 333 MANUFACTURING PROCESSES-II
INTRODUCTION TO
MANUFACTURING & PRODUCTION
Lecturer(s):
Prof. Dr. Ömer EYERCİOĞLU&
Asst.Prof.Dr. Oğuzhan YILMAZ
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Chapter 1 INTRODUCTION
1.1. WHAT IS MANUFACTURING?
Manus(hand)
Factus(make)
manufacture
Technologically: Manufacturing is the application of physical and chemical application of physical and chemical processesprocesses to alter the geometry, properties, and/or appearance of a given starting material to make parts or products including assembly of multiple parts.
Manufacturing Process
Machinery Tooling Power Labor
Scrap and Waste
Raw Material
Processed Material
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Economically: Manufacturing is the transformation of materials transformation of materials into items of greater value by means of one or more processing and/or assembly operations.
Manufacturing Process
Value added
Starting material Material in
processing Processed material
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MANUFACTURED PRODUCTS AND PRODUCTION QUANTITY
Final products made by the industries can be divided into two major classes:
Consumer goods: products purchased directly by consumers, eg TV, car, tires etc.
Capital goods : purchased by other companies to produce goods and supply services, eg. Aircraft, machine tools, construction equipment etc.
Production quantity refers to the number of units produced annually of a particular product type. The quantity (Q) of products made annually by a factory can be classified into three ranges:
low production Q<100medium production 100<Q<10 000high production 10 000<Q
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Product variety refers to different product designs or types that are produced in the plant.
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Product variety
Production quantity
Low
Medium
High
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Manufacturing is important: technologically, economically and historically.
TECHNOLOGY can be defined as the application of science to provide society and its members with those things that are needed or desired.
Manufacturing is the essential factor that makes technology possible.
Economically, manufacturing is important means by which a nation creates material wealth.
Historically, the importance of manufacturing in the development of civilization is usually underestimated. But throughout history human cultures that were better at making things were more successful.
The words PRODUCTION and MANUFACTURING are often used interchangeably. But production has a broader meaning production has a broader meaning than manufacturing. For example oil production seems better than oil manufacturing. We can use both for metal parts and automobiles.
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Manufacturing Processes
Processing Operations
Assembly Operations
Shaping Processes
Property Enhancing Processes
Surface Processing Operations
Casting, Molding, etc.
Particulate Processing
Deformation Processing
Material Removal
Heat Treatment
Cleaning and Surface Treatments
Coating and Deposition Processes
Welding
Brazing and Soldering
Adhesive Bonding
Threaded Fasteners
Permanent Fastening Methods
Permanent Joining Processes
Mechanical Fastening
Chapter 1 INTRODUCTION
Manufacturing Process Selection:
- Geometric features of the parts to be produced- Dimensional tolerances- Surface Texture- Workpiece Material etc.
Example:
• Flat parts and thin cross sections can be difficult to cast• Complex parts generally cannot be shaped easily and economically by such metal working techniques• Dimensional tolerances and surface finish in hot-working operations are not a fine as compared to cold working
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Near-shape and Near-net shape Manufacturing
• Net-shape and near net-shape manufacturing together constitute an important methodology by which a part is made in only one operation at or close to the FINAL desired dimensions, tolerances, and surface finish.
• The difference net-shape and near net-shape is a matter of degree how close the product is to its final how close the product is to its final dimensional characteristics.dimensional characteristics.
Example:• a cast or forged gear• crankshaft crank shaft forging die
Additive manufacturing part
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Chapter 1 INTRODUCTION
Precision and ultra precision Manufacturing
Micromechanical and microelectromechanical device fabrication needs highly sophisticated technologies and highly accurate equipments.
Micro machining uses 250 micrometer diameter cutting tool nose.
The equipments (or machines) used in precision or ultra precision manufacturing should be highly specialized, with very high stiffness ( to minimise deflection as well as vibration and chatter during machining) and should be operated in a temperature controlled enviroment in order to avoid thermal distortions.
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Chapter 1 INTRODUCTION
Computer-Integrated Manufacturing (CIM)
CIM integrates the software and hardware needed for computer graphics, computer-aided modelling and computer aided design and manufacturing activities, from initial product concept through its production and distribution in the market place.Elements of CIM:1.1.Computer numerical control (CNC)Computer numerical control (CNC)2.2.Adaptive Control (AC)Adaptive Control (AC)3.3.Industrial robotsIndustrial robots 4.4.Automated materials handlingAutomated materials handling5.5.Automated assembly systemsAutomated assembly systems6.6.Computer-aided process planning (CAPP) Computer-aided process planning (CAPP) : improving productivity, product quality, reducing costs. Cost estimating and monitoring etc.7.7.Group technology (GT)Group technology (GT)8.8.Just-in-time production (JIT):Just-in-time production (JIT): (1) supplies of the raw material and parts are delivered to the manufacturer just in time to be used, (2) parts and components are produced just in time to be made into subassemblies, and (3) products are assebled and finished just in time to be delivered to the customer
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Chapter 1 INTRODUCTION
Computer-Integrated Manufacturing (CIM)
9. Cellular Manufacturing (CM):9. Cellular Manufacturing (CM): Different operations are made in different cell
10. Flexible manufacturing systems (FMS):10. Flexible manufacturing systems (FMS):
11. Expert Systems (ES)11. Expert Systems (ES)
12. Artificial Intelligence (AI)12. Artificial Intelligence (AI)
13. Artificial Neural network (ANN):13. Artificial Neural network (ANN): simulates human brain with such capabilities as modelling and simulating production facilities, monitoring and controlling manufacturing process, diagnosing problems in machine performance etc.
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Chapter 1 INTRODUCTION
1.2. PRODUCTION SYSTEMS
CONTINUOUS MASS &FLOWLINE
BATCH GROUP TECHNOLOGY
SINGLE ONE OFF
TYPES OF PRODUCTION
Continuous Production: The material or product to the same specification is produced continuously for 24 hrs daily throughout the year produced continuously for 24 hrs daily throughout the year except for maintenance or seasonal variation of raw material supply.
•highly automated and specialised process: uses special machinery and equipment•if the process is stopped even for a short time, damage of materials and equipment will occur•oil refineries, iron and steel production are the examples.
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Mass and flowline production: It covers mechanical items to be manufactured one after the other to the same specifications throughout the year in 1, 2, or 3 shifts until the model changes
• the demand must be in large quantities• highly automated transfer and special purpose machines are used involves heavy capital expenditure on plant• manufacture of motor cars is an example.
Batch Production (Job lot or intermittent): Processes items when and as ordered. Small lot of items is ordered and once the lot is completed it is likely that it will never be manufactured again.
• flexibility of operations is very important• general purpose automatic machines are used• degree of automation depends on production volume (generally small volume items)• same product may be produced several times a year at different dates
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Group Technology (GT or cellular) Production: GT is the definition of identifying and bringing together related or similar parts in a production process in order to utilize the inherent economy of flow production methods. GT in manufacturing is the replacing of traditional job lot manufacture by analysis and grouping of work into families (size, shape, families (size, shape, material, tolerance, surface finish and required production operations) material, tolerance, surface finish and required production operations) and formation of groups of machines to manufacture these families on a flowline principle with the object of minimising setting times and throughput times.
One Off Production to Order: (Single Production) Single or few machinery, equipment or vessels are manufactured to a specified design.general purpose machine tools for specific sizes are usedautomation is not considered general except weldingproduction of marine gearboxes, ship building are the examples.
Production for Repair and Maintenance: No new end product except that the present one is repaired.
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1.3. ORGANIZATION OF PRODUCTION Plant Layout is a plan, or the act of planning, an optimum arrangement of act of planning, an optimum arrangement of industrial facilities, including personal, operating equipment, storage space, industrial facilities, including personal, operating equipment, storage space, material handling equipment, and all other supporting services material handling equipment, and all other supporting services with the design of the best structure to contain these facilities.
MEN
MACHINE
Materials
Supporting activities
THE BEST
LAYOUT
FIXED POSITION LAYOUT
PROCESS LAYOUT
CELLULAR LAYOUT
PRODUCT LAYOUT
TYPES OF LAYOUT
In practice, most factories are laid out using a combination of these layouts22
Chapter 1 INTRODUCTION
Product remains in a fixed position
Labour
Materials
Tools
Characteristics: least important todaye. g. shipbuilding, house building, large assembly worksAdvantages: Allows worker to identify with a particular product which can results in high job satisfaction and high quality standardsFlexible: allows frequent product or design changesMay reduce investment in mechanical handling equipmentAdaptable to changes in demand.Disadvantages:High degree of skill required. This can limit flexibility and put up cost of labourMay cause scheduling problems where more than one group of workers is involved.
1.3.1. FIXED POSITION LAYOUT
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1.3.2. PRODUCT LAYOUT
C GMTD
Raw Material
Finished product
Characteristics:only one type of product are produced, machines are arranged in the order of operationthe product must be standardized and manufactured in large quantitiesAdvantages:high through-putusually less skilled labour requiredlower total material handling costlower total production timeless work-in-progresshigh level of performance due to greater incentive for group of workersless floor area required per unit of productionsimple production control, fewer records and lower accounting costDisadvantages:Inflexible to design, processing and volume changesHigh initial capital investment requiredSusceptible to absenteeism, breakdown and disputeDifficult lo balance lines
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Chapter 1 INTRODUCTION
1.3.3. PROCESS LAYOUT (FUNCTIONAL LAYOUT)
M M
M M
T T
T T
G G:
G G
C C
CCharacteristics: groups together all operations of the same workpiece passes from department to department according to sequence of operations to be performedAdvantages:flexible: can cope with a wide variety of products, frequent design changes and varying demandeasy to maintain continuity in the case of breakdown or absenteeism by transferring work to another machineless duplication of equipment, hence lower total investment in equipmentbetter and more efficient supervision possible through specializationhigh level of performancebetter control of processDisadvantages:high cost of material handlinglower through-puthigh work-in-progressskilled labour is requiredextensive scheduling and control required 25
Chapter 1 INTRODUCTION
USE PRODUCT LAYOUT WHEN
USE PROCESS LAYOUT WHEN
One or few standard product Many types or styles of products
Large volume of production of each item
Relatively low volume of individual product
Possibility of motion and time studies to determine rate of work
Adequate motion and time studies difficult or impossible to make
Possibility of good labour and equipment balance
Difficult to achieve labour and equipment balance
Minimum of inspection required during sequence of operations
Many inspection required during sequence of operations
Minimum of very heavy equipment requiring special facilities
High portion of very heavy equipment requiring special facilities
Materials and products permit bulk or continuous handling by mechanical means
Materials and products are too large or too heavy to permit bulk or continuous handling by mechanical means
Little or no need to use same machine or work station for more than one operation
Frequent need to use same machine work station for more than one operation
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1.3.4. GROUP TECHNOLOGY (CELLULAR LAYOUT)
M
MM M
T
T
T T
G G:
G CCC
Characteristics: groups together similar parts Mass and flowline principle is applied to each cell
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Chapter 1 INTRODUCTION
MANUFACTURING COSTS
The economics of manufacturing has become even more so with;(a)ever-increasing global compition (b)The demand for the high quality products
Typically, the manufacturing cost of a product represents about 40% ot its selling price, which often is the overriding consideretion in a product marketability and general customer satisfaction
The total costs of manufacturing of a product generally consits of the following components:1.Materials: raw material costs2.Tooling: cutting tools, dies, molds, workholding devices, and fixtures.3.Fixed: Cost of energy, rent for facilities, insurance and real-estate taxes4.Capital: production machinery, equipment, buildings, and land5.Labor: Direct and indirect costs. Direct labor is productive labor which directly related to the production. Indirect laboring is for servicing of the total manufacturing operations.
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Product Design and Concurent Engineering
Product design involves the creative and systematic prescription of the shape and the characteristics of an artifact to achieve specified objectives while simultaneously satisfiying several constraints.
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Concurent Engineering (Simultaneous engineering): The applications of tools, techniques, methodologies, and behavioral, initiatives used to minimize product development timescales by maximizing the degree of overlap of design activities
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Green Design and Manufacturing OR Green Manufacturing
Every year millions of cars, tires, lamps, plastic prodcuts etc are discarded. From manufacturing point of view; manufacturing operations generally produce waste, such as:- chips- slag- additives (sand casting operations)- hazardous waste- lubricants and coolants- processed liquids- solvents- smoke and pollutants
Green design concerns with selection of enviromentally friendly design, selection of material and manufacturing processes.
Green manufacturing is now concerning of reusing the waste products and recylicing them in an effective way.
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