Chapter 1 - INTRODUCTION AND OVERVIEW OF MANUFACTURING

Manufacturing Support Systems

A company must organize itself to design the processes and equipment, plan and control production, and satisfy product quality requirements - Accomplished by manufacturing support systems --The people and procedures by which a company manages its production operations. - Typical Departments -- Manufacturing engineering, production planning and control, quality control.

Processing Operations

Alters a materials shape, physical properties, or appearance in order to add value. Three Categories 1. Shaping operations - Alter geometry of the starting work material. 2. Property - Enhancing operations - Improve physical properties without changing shape 3. Surface processing operations - clean, treat, coat, or deposit material on surface work.

Manufacturing - Technological

Application of physical and chemical processes to alter the geometry, properties, and/or appearance of a starting material to make parts or products.

Surface Operations

Cleaning - CLeaning and mechanical processes to remove dirt, oil, etc Surface Treatments - Mechanical working such as sand blasting, and physical processes like diffusion. Coating and Thin Film - Coating exterior surface of the work part. - e.g. , Electroplating, painting

Polymers

Compound formed of repeating structural units called mers, whose atoms share electrons to form large molecules. Three categories. 1. Thermoplastic Polymers - Can be subjected to multiple heating and cooling cycles without altering molecular structure 2. Thermosetting Polymers - Molecules chemically transform into a rigid structure, cannot reheat. 3. Elastomers - Shows significant elastic behavior.

Ceramics

Compounds containing metallic ( or semi - metallic ) and nonmetallic elements. - Typical nonmetallic elements are oxygen, nitrogen, and carbon. - Two Types Crystalline Ceramics - Includes traditional ceramics, such as clay, and modern ceramics, such as alumina Glasses - Mostly based on silica.

Manufacturing Industries

Consists of enterprises and organizations that produce or supply goods and services Can be classified as : 1. Primary Industries, - Cultivate and exploit natural resources, e.g. , agriculture, minning 2. Secondary Industries - Take the outputs of primary industries and convert them into consumer and capital goods. 3. Tertiary Industries - Service Sector (Retail, Hotel, Etc)

Technology

Defined as the application of science to provide society and its members with those things that are needed or desired. Technology affects our daily lives, directly and indirectly, in many ways

Production Capacity

Defined as the maximum quantity that a plant can produce in a given time period (e.g time of year) under assumed operating conditions. - Operating condition refer to number of shifts per week, hours per shift, direct labor manning levels in the plant, and so. - Usually measured in terms of output units, e.g. , tons of steel or number of cars produced. - Also called plant capacity.

Waste in Shaping Processes

Desirable to minimize. Material removal wasteful in unit operations, Molding/Particulate processing waste little material. - Net Shape Processes - Little or no waste of the starting material and no machining is required - Near net shape processes - When minimum machining is required

Environmentally Conscious Manufacturing

Determining the most efficient use of materials and natural resources in production, and minimizing the negative consequences on the environment Associated Terms: Green manufacturing, cleaner, production, sustainable manufacturing Basic Approaches: - Design products that minimize environmental impact - Design Processes that are environmentally friendly.

Computerization of Manufacturing

Direct Number Control (DNC) was one of the first applications of computers in manufacturing (1960s) - Mainframe computer remotely controlling multiple machine tools Enabled by advances in microelectronics, the cost of computers and data processing has been reduced, leading to widespread use of personal computers - To control individual production machines - To manage the entire enterprise

Microelectronics

Electronic devise that are fabricated on a microscopic scale: Integrated circuits - Today fabrication technologies permit billions of components to be included in a single IC - A large proportion of the products manufactured today are based on microelectronics technology. -- about 2/3 of the products 1.1 are either electronic products or their function and operation depend on electronics.

Metals

Generally Alloys, which are composed of two or more elements, at least one of which is metallic. Ferrous - Based on iron, comprises about 75% of metal tonnage in the world (e.g. , steel and cast iron) Non - Ferrous - All other metallic elements and their alloys. (e.g. , Aluminum, copper, nickel, silver, tin, etc. )

Physical Product Limitations

Given a plant with certain set of processes, there are size and weight limitations on the parts or products that can be made in the plant. Product size and Weight affect: - Production Equipment - Material handling equipment Production, material handling equipment, and plant size must be planned for products that lie within a certain size and weight range.

Production Quantity Q

Has an important influence on the way its people, facilities, and procedures, are organized. Three Ranges Low 1 to 100 Medium 100 to 10,000 High 10,000 to Millions of units.

Low Production

Job Shop term used for this type of production Makes low quantities of specialized and customized products - Products are typically complex e.g. , space capsules, prototype aircraft, special machinery. - Equipment in a job shop is general purpose - Labor force is highly skilled - Designed for maximum flexibility

Lean Production and Six Sigma

Lean Production - Doing more work with fewer resources, yet achieving higher quality int he final product - Underlying objective: Elimination of waste in manufacturing Six Sigma - Quality Focused program that utilizes worker teams to accomplish projects aimed at improving an organization organization performance.

Production Machines and Tooling

Manufacturing operations are accomplished using machinery and tooling. Types of Production Machines, Machine Tools : Power Driven Machines used to operate cutting tools previously operated manually. Others, - Pressed - Forge Hammers - Plastic Injection Molding machines.

Secondary Industries

Manufacturing, construction, and electric power generation. (Manufacturing covers, Nuts and bolts, forgings, cars, airplanes, digital computers, plastic parts, and ceramic products.

Quantity Production

Mass production of single prats on single machine or small numbers of machines - Typically involve standard machines equipped with special tooling - Equipment is dedicated full time to the production of one part of product type = Typical layouts used in quantity production are process layout and cellular layout.

Composites

Material consisting of two or more phases that are processed separately and then bonded together to achieve properties superior to its constituents. Phase - Homogeneous material, such as grains of identical unit cell structure in solid metal. Usual structure consists of particles or fiber of one phase mixed in a second phase Properties depends on the components, physical shapes of components and the way they are combined to form the final material.

Engineering Materials

Metals - Ferrous/Non - Ferrous Ceramics - Crystalline/Glasses Polymers - Thermoplastics/Thermosets/Elastomers Composites - Metal Matrix/Ceramic Matrix/ Polymer Matrix (Composites)

Micro fabrication and Nanotechnology

Micro fabrication - Processed that make parts and products whose feature sizes are in the micron range (10 to -6) - e.g. , ink - jet printing heads, compact disks, micro sensors used in automobiles Nanotechnology - Materials and products whose feature sizes are in nano meter range ( 10 to -9 ) - e.g. , coatings for catalytic converters, flat screen TV monitors.

Recent Developments

Microelectronics Computerization of Manufacturing Flexible Manufacturing Micro fabrication and Nanotechnology. Lean Production and Six Sigma Globalization and outsourcing Environmentally Conscious Manufacturing

Material in Manufacturing

Most engineering materials can be classified into one of three basic categories: 1. Metals 2. Ceramics 3. Polymers - Chemistries are different and their mechanical properties and physical properties are different. - Composites ( Additional fourth category)

Flow Line Production

Multiple Machines or workstations arranged in sequence, as in production line - Product is complex - requires multiple processing and/or assembly operations - Work units are physically moved through the sequence to complete the product - workstations and equipment are designed specifically for the product to maximize efficiency.

High Production

Often referred as mass production - High demand for product - Manufacturing systems dedicated to the production of that product. Two Categories - Quantity Production - Flow Line.

Production Systems

People, Equipment, and procedures used for the materials and processes that constitute a firm's manufacturing operations. A manufacturing firm must have systems and procedures to efficiently accomplish its production Two Categories ; - Production Facilities - Manufacturing Support Systems.

Property Enhancing Processes

Processes that improve mechanical or physical properties of work material. - e.g. , heat treatment of metals and glasses, sintering of powdered metal and ceramics Part shape is not altered, except unintentionally - Unintentional warping of a heat treated part.

Hard Product Variety

Products differ substantially, e.g., between a small car and a large truck, with a few common parts (if any)

Product Variety P

Refers to Different product types or models produced in the plant. Have different features, - Intended for different markets - Some have more parts than others. Number of different product types made each year in a factory can be counted When the number of product types made is high, this indicated high product variety.

Processing Operations

Shaping Processes Property Enhancing Processes Surface Processing Operations

Soft Product Variety

Small differences between products, e.g., between car models made on the same production line, with many common parts.

Shaping Processed

Solidification Processes Particulate Processing Deformation Processes Material Removal

Material Removal Processes

Starting Material is a ductile solid. Excess material removed from the starting piece so what remains is the desired geometry - Turning, Drilling, and milling

Particulate Processing

Starting material consists of powders. - Starting materials Metal or ceramic Powders, which are pressed or sintered.

Deformation Processes

Starting material is a ductile solid. Shaped by applications of forces that exceed the yield strength of the material. - Forging - Extrusion

Solidification Processes

Starting material is heated to a liquid or semifluid 1. Casting Process 2. Casting Product.

Production Facilities

The factory, production equipment, and material handling systems. Includes plan layout Equipment usually organized into logical groupings, called manufacturing systems. e.g. , Automated Production Line Machine Cell consisting of three machine tools Production facilities "touch" the product.

Globalization

The recognition that we have an internation economy in which barriers once established by national boundaries have been reduced - This has enabled the freer flow of goods and services, capital, technology, and people among regions and countries. - Once underdeveloped countries such as China, India, and Mexico, have now developed their manufacturing infrastructures and technologies to become important producers in the global economy.

Technological Processing Capability

The set of available manufacturing processes in the plant ( or company) Certain processes are suited to certain materials, so be specializing in certain processes, the plant is also specializing in certain materials. Includes not only the physical processes, but also the expertise of the plant personnel. - A machine shop cannot roll steel - A steel mill cannot build cars.

Mechanical Fastening

Threaded Fasteners Permanent Fastening Methods.

Manufacturing Capability

Three Building Blocks, Materials, Processes, and systems. 1. Technological processing capability. 2. Physical product limitations 3. Production capacity.

Manufacturing - Economic

Transformation of materials into items of greater value by one or more processing and/or assembly operations.

Manufacturing Processes

Two Basic Types, Processing Operations - Transform a work material from one state of completion to a more advanced state Assembly Operations - Join two or more components to create a new entity.

Manufactured Products

Two Major Classes 1. Consumer Goods - Purchased Directly by consumers. 2. Capital Goods.- Purchased by Companies to produce goods and/or provide services.

Medium Production

Two different types of facilities - Batch - Suited to medium and hard product variety - Setups required between batches - Cellular Manufacturing - Suited to soft product variety - Worker cells organized to process parts without setups between different part styles.

Assembly Operations

Two or more separate parts are joined to form a new entity Joining - Create a permanent joint, Welding, brazing, soldering, adhesive bonding Mechanical Assembly - Fastening by mechanical - Threaded fasteners (screws, bolts, and nuts), press fitting, expansion fits.

Outsourcing

Use of outside contractors to perform work that was traditionally accomplished in-house Local outsourcing - Jobs remain in the US Outsourcing to foreign countries - Offshore outsourcing - Production in China and other overseas locations - Near shore outsourcing - Production in Canada, Mexico, and Central America.

Permanent Joining Processes

Welding Brazing and Soldering Adhesive Bonding