Chapter 1: Introduction

1
Chapter 1 Introduction

• What is mfg?
• Mfg the process of converting raw materials
  into products by means of various processes,
  machinery, and operations, through a
  well-organized plan for each activity required.
• It encompasses
• the design of the product
• the selection of raw materials
• the sequence of processes through which the
  product will be manufactured.
• The higher the level of mfg activity in a
  country, the higher the standard of living of its
  people.
• Mfg has the important function of adding value to
  a mfg product defined as monetary worth or
  marketable price. For example clay and ceramic
  cutting tool .

2
Introduction

• Mfg activities must be responsive to several
  demands and trends
• A product must fully meet design requirements
  products specs standards.
• A product must be mfg by the most environmentally
  friendly economical methods
• Quality must be built into the product at each
  stage.
• Production methods must be flexible enough to
  respond to changes in market demands, types of
  products, production rates, Quantities, and
  on-time delivery req.
• New developments in materials, production
  methods, and computer integration of both
  technological and managerial activities in a mfg
  org must constantly be evaluated with a view to
  their appropriate, timely, economical
  implementation.
• Mfg activities must be viewed as a large system,
  the parts of which are interrelated. Such systems
  can be modeled, in order to study the effects of
  factors such as changes in market demands, prod
  design, and materials.
• Constantly strive for higher levels of quality
  and productivity. Output per employee per hour in
  all phases must be max. Zero-based part rejection
  are also an integral aspect of mfg

3
Example of mfg product Paper clip

• What type of material? Metallic or non metallic?
• If metal what kind of metal?
• If the mat you start with is wire, what should be
  its diam?
• Should it be round or have some other x-section?
• Is the wires surface finish appearance
  important? What should it be its roughness?
• How would you take a piece of wire shape it
  into a paper clip?
• Would you do it by hand? If not , what kind of
  machine should you design or purchase to make
  paper clips?
• If, as the owner of a comp, you were given an
  order for 100 parts vs for a million parts, would
  your approach to mfg be diff?
• Design requirements
• Function hold pieces of paper .
• Mat selected must have a certain stiffness
  strength.
• If the yield stress is too low, the clip will
  bend permanently
• Stiffness also depends on wire diameter
• Style, appearance, and surface finish

4
Example of mfg product Paper clip

• Material Selection
• Material selection requires knowledge of function
  and service requirements of the product.
• Therefore, choosing materials that are
  commercially available.
• Corrosion resistance must also be considered
• Questions regarding prod of paper clip
• Will the mat selected be able to undergo bending
  during mfg without cracking or breaking?
• Can the wire be easily cut from a long piece
  without causing excessive wear on tooling?
• Will the cutting process produce a smooth edge on
  the wire or it will leave a burr?
• What is the most economical method of mfg this
  part at the desired prod rate?

5
The design process concurrent engineering

• The design process for a product first requires a
  clear understanding of the functions the
  performance expected of that product.
• The market for a product and its anticipated uses
  must be defined clearly.
• Product design is a critical activity
• 70 to 80 of the cost of product development
  and manufacture is determined by the decisions
  made in the initial design stages.

6
Traditional product cycle
Definition of product need marketing information
Conceptual design evaluation feasibility study
Design analysis codes/standards review physical
and analytical model
CAD
Prototype production testing evaluation
Production drawings instruction manuals
Material specs process equipment selection
safety review
CAM CAPP
Pilot production
Production
CIM
Inspection quality assurance
Packaging marketing sales literature
Product
7
The design process concurrent engineering

• Traditional product cycle
• While the traditional approach seems logical and
  straightforward in theory, it has been found in
  practice to be extremely wasteful of resources.
• For example, a mfg engineer may wish to taper the
  flange on a part to improve its castability or
  may decide that a different alloy is desirable.
• such changes necessitate a repeat of the design
  analysis stage, in order to ensure that the
  product will still function satisfactorily .
  these iterations, certainly waste resources, but
  more importantly, they waste time.

8
The design process concurrent engineering

• Concurrent Engineering (CE)
• CE is a systematic approach integrating the
  design and mfg of products, with a view toward
  optimizing all elements involved in the life
  cycle of the product.
• Life cycle means that all aspects of a product,
  such as design, development, production,
  distribution, use, disposal, and recycling, are
  considered simultaneously.
• basic goals of CE
• reduce changes in products design engineering.
• reduce time and costs involved in taking the
  product form its design concept to its production
  and its introduction into the marketplace.

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The design process concurrent engineering

• A well-designed product is
• functional (design)
• well-manufactured (production)
• well-packaged (distribution)
• durable (functions effectively for its intended
  life)
• maintainable (use)
• resource-efficient (can be disassembled so that
  components can be recycled-disposal)
• For CE to succeed, it must
• have the full support of upper management
• have multifunctional and interactive teamwork,
  including support groups
• utilize all available technologies.
• Example of the benefits of CE One automotive
  company has reduced No. of parts in one of its
  engines by 30, and as a result has decreased
  that engines weight by 25 and cut its mfg time
  by 50 .

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The design process concurrent engineering

• CAD allows the designer to conceptualize objects
  more easily without having to make costly
  illustrations, models, or prototypes.
• Using CAE, the performance of structures
  subjected to static or fluctuating loads and to
  varying temperatures can now be simulated,
  analyzed, and tested more efficiently,
  accurately, and quickly than ever. Designs can be
  optimized, and modifications can be made,
  directly and easily, at any time.
• CAM CNC of machines programming robots for
  material handling assembly, designing tools,
  dies, fixture maintaining quality control.
• On the basis of the models developed using the
  foregoing techniques, the product designer
  selects and specifies the final shape
  dimensions of the product, its dimensional
  accuracy and surface finish, and its component
  materials.
• The next step in the production process is to
  make and test a prototype.
• Tests of prototypes must be designed to simulate
  as closely as possible the conditions under which
  the product is to be used.
• During testing of prototypes, modifications in
  the original design, materials, or production
  methods may be necessary. After this phase has
  been completed, appropriate process plans, mfg
  methods, equipment, and tooling are selected,
  with the co-operation of mfg engineers, process
  planners, and others involved in production.

11
DFM, DFA, DFS

• DFM is a comprehensive approach to production of
  goods, and it integrates the design process with
  materials, mfg methods, process planning,
  assembly, testing, and quality assurance such
  that the product can be manufactured economically
  and efficiently
• Assembly is an important phase of the overall mfg
  operation and requires consideration of the ease,
  speed, and cost of putting parts together. Also,
  many products must be designed so that
  disassembly is possible, in order to enable the
  product to be taken apart for maintenance,
  servicing, or recycling of its components.
• Design for service, the goal of which is that
  individual parts or sub-assemblies in a product
  be easy to reach and service.
• The trend now is to combine DFM and DFA into the
  more comprehensive DFMA.

12
Selecting materials

• Types of materials used in mfg
• Ferrous metals.
• Nonferrous metals.
• Plastics thermoplastics, thermosets, and
  elastomers .
• Ceramics, glass ceramics, glasses, graphite,
  diamond.
• Composite materials.
• Nano-materials, shape-memory alloys, amorphous
  alloys, superconductors.
• Properties of materials
• When selecting materials for products
• consider their mechanical properties.
• consider the physical properties of materials.
• Chemical properties also play a significant role,
  both in hostile and in normal environments
  Oxidation, corrosion, toxicity, and flammability.
• Mfg properties of materials determine whether
  they can be cast, formed, machined, welded,
  heat-treated with relative ease. Methods used
  to process materials to desired shapes can
  adversely affect products final properties,
  service life, cost.

13
Selecting materials

• Cost and Availability
• The economic aspects of material selection are as
  important as tech. considerations of properties
  chac. of materials.
• If raw or processed materials or mfg components
  are not available in the desired shapes,
  dimensions, and quantities, substitutes and/or
  additional processing will be required, and they
  can contribute significantly to product cost.
• A product design can be modified to take
  advantage of standard dimensions of raw materials
  and thus avoid extra mfg costs.
• Reliability of supply, as well as demand, affects
  cost.
• Different costs are involved in processing
  materials by different methods.
• Appearance, Service life, and recycling
• Color, feel, and surface texture.
• Time service dependent phenomena such as wear,
  fatigue, creep, and dimensional stability are
  important.
• Friction wear, corrosion, and other phenomena
  can shorten products life or cause it to fail
  permanently.
• Recycling of or proper disposal of component
  materials at the end of products useful service
  life for maintaining clean and healthy envir.
• Proper treatment and disposal of toxic wastes and
  materials.

14
Selecting mfg processes

• Casting
• Forming and shaping.
• Machining.
• Joining.
• Finishing.
• Brittle and hard materials, for example, cannot
  be shaped easily, where-as they can be cast or
  machined readily by several methods.
• The mfg process usually alters the properties of
  materials. Metals that are formed at room
  temperature become stronger, harder, and less
  ductile than they were before processing.
• Dimensional accuracy and surface finish
• Size, thickness, and shape complexity of part
  have a major bearing on the mfg process selected
  to produce it.
• Flat parts with thin x-sections cannot be cast
  properly.
• Complex parts cannot be formed easily and
  economically, whereas they may be cast or else
  fabricated from individual pieces.
• Tolerances and surface finish obtained in
  hot-working operations cannot be as good as those
  obtained in cold-working operations.

15
Selecting mfg processes

• Operational and mfg costs
• The design cost of tooling, lead time required
  to begin production, the effect of wp material
  on tool life and die life are major
  consideration.
• For parts made from expensive materials, the
  lower the scrap rate, the more economical the
  production process will be.
• Availability of machines and equipment and of
  operating experience within the mfg facility are
  also important cost factors.
• No. of parts required and the required production
  rate are important in determining the processes
  to be used and the economics of production.
• Operation of machinery has significant
  environmental safety implication.
• The safe use of machinery is another important
  consideration.

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selecting mfg processes

• Consequences of Improper Selection of Materials
  Processes
• A component or a product is generally considered
  to have failed when
• It stops functioning (broken shaft, gear, bolt,
  or turbine blade).
• It does not function properly or perform within
  required specification limits (worn bearings,
  gears, tools, and dies).
• It becomes unreliable or unsafe for further use
  (crack in a shaft, poor connection in a PCB).
• Product failures Result from
• design deficiencies
• improper material selection
• material defect
• mfg-induced defects
• improper component assembly
• improper product use.
• Net-shape mfg
• The part is made, in the first operation, as
  close to the final desired dimensions,
  tolerances, surface finish , and specifications
  as possible.

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Selecting mfg processes

• Computer Integrated Mfg
• The major goals of automation in mfg facilities
  are to integrate various operations so as to
• improve productivity.
• increase product quality and uniformity.
• minimize cycle times.
• reduce labor costs.
• CIM is effective because of its capability for
  making possible
• responsiveness to rapid changes in market demand
  and product modification
• better use of materials, machinery, personnel,
  reduction in inventory.
• better control of production management of the
  total mfg operation.
• the manufacture of high-quality products at low
  cost.

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Computer Integrated Mfg

• CNC
• Adaptive Control (AC) parameters in a mfg
  process are adjusted automatically to optimize
  production rate and product quality and to min
  cost. Parameters are monitored constantly. If
  they move outside the acceptable range, the
  system adjusts the process variables until the
  parameters again fall within the acceptable
  range.
• Industrial robots Replacing humans in operations
  that are repetitive, boring, and dangerous, thus
  reducing possibility of human error, decreasing
  variability in product quality, and improving
  productivity.
• Automated handling of materials.
• CAPP this tool is capable of improving prod in
  plant by optimizing process plans, reducing
  planning costs, improving the consistency of
  prod quality reliability. Functions such as
  estimating of cost and the monitoring of work
  standards (time req to perform a certain
  operation) can also be incorporated into the
  system.

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Computer Integrated Mfg

• JIT supplies are delivered JIT to be used, parts
  are produced JIT to be made into sub-assemblies
  and assemblies, and products are finished JIT to
  be delivered to the consumer. In this way,
  inventory-carrying costs are low, part defects
  are detected right away, prod is increased, and
  high quality products are made at low cost.
• Cellular mfg.
• FMS integrates mfg cells into a large unit, all
  interfaced with a central computer. FMS have the
  highest level of efficiency, sophistication, and
  prod among mfg systems. They are capable of
  efficiently producing parts in small runs and of
  changing mfg sequences on diff parts quickly
  this flexibility enables them to meet rapid
  changes in market demand for various types of
  products.
• AI use of machines computers to replace human
  intelligence. Computer controlled systems are
  becoming capable of learning from experience of
  making decisions that optimize operations and min
  costs.
• Artificial neural networks, which are designed to
  simulate the thought processes of human brain,
  have the capability of modeling simulating
  production facilities, monitoring controlling
  mfg processes, diagnosing problems in machine
  performance, conducting financial planning, and
  managing a companys mfg strategy.
• Shared mfg.

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Quality Assurance TQM

• Quality
• is a char or property of several well defined
  technical (objective) and aesthetic (subjective)
  considerations.
• General public perceptions is that a high
  quality product functions reliably and as
  expected over a long period of time.
• Traditionally, QA has been obtained by inspecting
  parts after they have been mfg. Parts are
  inspected to ensure that they conform to a
  detailed set of specs and standards such as
  dimensions, surface finish, and mech physical
  properties
• New approach quality must be built into a
  product, from the design stage through all stages
  of mfg and assembly.
• The objective should be to control processes, not
  products.
• low quality products do not necessarily cost less
  to mfg than high quality products do.
• Product integrity
• Product integrity is a term that can be used to
  define the degree to which a product
• is suitable for its intended purpose.
• Fills a real market need
• Functions reliably during its life
• Can be maintained with relative ease
• Product integrity has also been defined as the
  total product experience of the customer, or as
  the totality of qualities needed to conceive,
  produce, and market the product successfully

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Quality Assurance TQM

• TQM and QA
• TQM and QA are now the responsibility of everyone
  involved in designing and mfg a product.
• The major goal is to prevent defects from
  occurring, rather than to detect and reject
  defective products after they are made.
• QA standards
• ISO 9000 series on quality management and QA
  standards, as well as QS 9000.
• A companys registration for this standard, which
  is a quality process certification and not a
  product certification, means that the company
  conforms to consistent practices as specified by
  its own quality system.
• DFMA and concurrent engineering
• The design should make the product as simple as
  possible to mfg, assemble, disassemble, and
  recycle.
• Mat should be chosen for their appropriate mfg
  char.
• Dim accuracy and surface finish should be
  specified as broadly as is permissible, in order
  to minimize mfg costs.
• Secondary and finishing operations on parts
  should be avoided or minimized, because they can
  add significantly to cost.

22
Global Competitiveness mfg Costs

• Total cost of mfg a product
• Consists of the costs of mat, tooling, and labor,
  the fixed costs, and capital costs.
• Mfg costs can be min by analyzing the product
  design to determine whether the part size and
  shape are optimal and whether the mat selected
  are the least costly ones that possess the
  desired properties and char.
• Tooling costs depend on
• Complexity of part shape
• Material involved
• mfg process
• The no. of parts to be made.
• Direct labor costs are usually only a small of
  the total cost (10-15 ).
• The trend toward increased automation and toward
  computer control of all aspects of mfg helps to
  min labor involvement and so to reduce direct
  labor costs.
• Fixed costs and capital costs depend on the
  particular mfg and plant facilities.

23
Lean Production and Agile mfg

• Lean production (LP)
• LP involves a major assessment of each of the
  activities of a company
• efficiency effectiveness of its various
  operations.
• possibility of dispensability of some of its
  operations managers
• efficiency of machinery and equipment in the
  operation.
• No. of personal involved in each particular
  operation.
• It continues with a thorough analysis of the
  costs of each activity, including those due to
  productive and non-productive labor.
• This concept req a fundamental change in
  corporate culture as well as understanding of the
  importance of cooperation teamwork between
  management and the work force.
• Its results do not necessarily req cutting back
  to resources, rather it aims at continually
  improving the efficiency profitability of the
  company, by removing all waste from the
  operations and by dealing with problems right
  away.
• Agile mfg (AM)
• The use of the principles of LP on a broad scale.
• The principle behind AM is ensuring agility,
  hence flexibility, in the mfg enterprise, so that
  it can respond quickly to changes in product
  demand and in customer needs.
• This flexibility is to be achieved through
  people, equipment, computer hardware and
  software, and sophisticated comm. Systems. (3W)

24
Environmentally Conscious Design Mfg

• Environmentally-Conscious Design and Mfg
• This approach anticipates the possible -ve
  environmental impact of mat, products,
  processes, so that it can be taken into account
  at the earliest stages of design and mfg.
• Reducing waste of mat at their source, by
  refining in product design and by reducing the
  amount of mat used.
• The main objectives now are preventing pollution
  at the source and promoting recycling and reuse
  in place of disposal.
• Design for Recycling (DFR) Making improvements
  in recycling, in waste treatment, and in reuse of
  mat.
• Conducting research and development into
  environmentally-safe and into mfg technologies.
• Reducing the use of hazardous mat in products and
  processes
• Ensuring proper handling and disposal of all
  waste
• Product Liability
• Product liability The consequences of a
  products malfunctioning and possibly causing
  bodily injury (or even death) and financial loss
  to a person or org
• Human factors engineering and ergonomic
  considerations are important aspects of the
  design and mfg of safe products.

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Organization for Mfg

• Traditional Major responsibilities of Mfg
  engineers
• plan the mfg of a product the processes to be
  utilized.
• identify machines, equipment, tooling, and
  personal to carry out the plan.
• interact with design and mat engineers to
  optimize productivity and min production costs.
• cooperate with industrial engineers when planning
  for plant-floor activities, on such topics as
  plant layout, machine arrangement, selection of
  material-handling equipment, time motion study,
  production methods analysis, production planning
  scheduling, and maintenance.
• Traditional operational philosophy of mfg orgs
• emphasis was on top-down comm. In the org and on
  strong control by management, with priorities for
  quick financial return (profits 1st) and growth
  and size (economy of scale).
• emphasized the business and financial aspects of
  a comp, keeping mfg subordinate to the overall
  marketing plan.

26
Organization for Mfg

• Modern operational philosophy of mfg orgs
• broad-based comm. Across the org.
• Mfg has become an integral part of long-range
  business planning for companies that want to
  maintain their competitive positions and increase
  their market share.
• In order to respond to these major changes, its
  essential in a mfg org to
• View people in the org as important assets.
• Emphasize the importance and need for teamwork
  and involvement in problem solving and in
  decision making processes in all aspects of
  operations.
• Encourage product innovation and improvements in
  productivity.
• Relate product innovation and mfg to the customer
  and to the market. The product must be seen as
  meeting a need
• Increase flexibility of operation for faster
  response to product demands.
• Encourage efforts for continuous improvement in
  quality (quality 1st).
• customer satisfaction.