MANUFACTURING

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MANUFACTURING
(Lecture 4)
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Cycle of Manufacturing

• Manufacturing spans a large sequence of
  interrelated phases
• It involves research, development, design,
  production, quality control, selling and
  servicing of a product
• Research Development
• Research is an activity that looks at brand new
  ideas
• Development uses research to create new products
• Market research the current and recent trends
  in the market
• Look for a suitable material
• Recommend some choices of material to be chosen
• Keep on looking for the methods that could
  improve the comfort level, productivity of the
  current products
• Productivity is the ratio of the overall outputs
  to the inputs of a company

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Cycle of Manufacturing

• Design
• Decide the material, the size, color, and the
  shape etc.
• Assembly of a part in the forthcoming product is
  important in design
• Prototype a handmade test model of the product
• Plans for the steps of manufacturing the new
  product computer-aided design (CAD)
• The plans are later used by the production
  department
• Production
• Production department is responsible for actually
  making the companys product
• Schedule is a timed plan of activities
• Purchasing department has to procure the required
  type of raw material or parts
• The suppliers have to deliver the material
  according to production schedule

4
Cycle of Manufacturing

• Quality Control
• Quality control making sure that the products
  are all alike or uniform and according to the
  standards defined by the customer
• A standard is a system used for comparison
  helps your customers see the quality and
  performance easily
• The process starts from incoming quality control
  inspecting the raw materials
• Inspections are carried out at the end of
  assembly lines of different parts
• The final step is the inspection of the
  end-product
• Many companies check the quality control used by
  their suppliers
• A supplier gets their new products (prototypes)
  approved by the representative engineers of their
  customers before going onto large scale
  production
• After passing the test and being approved, a
  supplier receives a Supplier Certification Award
• Several groups American National Standards
  Institute (ANSI), American Society for Testing
  and Materials (ASTM), Society of Automobile
  Engineers (SAE)
• Measurement systems MKS System (meters and
  centimeters), FPS System (feet and inches)

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Cycle of Manufacturing

• Safety
• Safety means freedom from injury or any danger of
  injury
• Colorful and eye-catching signs are posted in a
  factory
• Occupational Safety and Health Administration
  (OSHA) establish safety rules
• National Institute of Occupational Safety and
  Health (NIOSH) approve protection equipment such
  as hard hats and safety glasses
• Environmental Protection Agency (EPA) restricts
  hazardous materials thrown into air or water,
  mostly from chemical plants
• Sales Marketing
• Marketing finding buyers for a companys
  product
• A company may sell its products to wholesalers or
  dealers
• Wholesaler a company that purchases large
  amounts from a manufacturer and then sells
  smaller amounts to retailers
• Retailer a company, or store, that sells
  products to consumers, e.g. Panda, Wal-Mart

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Cycle of Manufacturing

• Servicing
• After-sale-services products that need
  maintenance or that have been broken
• Warranty terms under which a company repairs or
  replaces a defective product
• The product becomes either a throwaway or a
  repairable product after the warranty period
• The company has its own repair shop or some
  dealers are responsible for this task

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Manufacturing Approaches

• Craftspeople, for centuries, make things on their
  own carpenters, shoemakers and glassblowers etc
• People used to run their own trade at their homes
  with a small setup
• This methodology of manufacturing is known as
  crafts approach
• Custom-made items are often made through crafts
  approach, e.g. an exotic sports car or products
  for handicapped people.
• Factory system came into being during industrial
  revolution people working under one roof
• Activities of workers could be tightly supervised
  (tasks assigned, output accurately measured and
  time attendance checked etc)
• Factory system has advanced a lot since its birth
• Factory system gave way to mass production and
  assembly line production
• Assembly line each worker does one step and
  passes the item on for the next step
• Assembly line products are standardized and
  interchangeable

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Manufacturing Approaches
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Manufacturing Approaches

• Factory system brought many changes to the
  society
• standard of living of the people living in
  industrialized nations improved
• unions were formed to protect the rights of
  workers
• child labor laws were passed
• the number and importance of schools and
  day-care-centers increased

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Contemporary Trends

• Automation is the process of controlling machines
  through computers
• A set of instructions called a program program
  control
• Sensors provide feedback to make modifications in
  these programs feedback control
• A sensor is a device that gathers information
  about its environment
• Automation has introduced concepts like robotics,
  CNC, CAD, CAM and CIM.
• Robotics technology that deals with the use of
  industrial robots
• An industrial robot has one mechanical arm and is
  controlled by a computer
• Robots do jobs that are hazardous, boring, or
  unpleasant for people
• They can be easily reprogrammed to do other tasks
• Uses of robotics spray painting, welding and
  pick-and-place jobs etc.
• CNC computerized numerical control machine
  tools operating through commands from a computer

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Contemporary Trends

• CAD computer aided design designing and
  planning activities related to a part
• CAM computer-aided manufacturing programming
  computers to operate all the machinery
• CIM computer-integrated manufacturing all the
  computers in the company are linked together, or
  integrated
• Uses of CIM
• design and production departments can communicate
  instantly
• purchasing department can tell their suppliers
  when to deliver production materials
• marketing department can plan when to start
  selling products
• management can direct the entire company from one
  location.
• Other trends in the modern industry JIT and
  Flexible Manufacturing
• JIT no storage cost, the raw material arrive at
  the factory only when it is required
• Flexible Manufacturing using the same set of
  machines and assembly lines for different models
  small batches

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Contemporary Trends
Cutting a T-shaped profile from a block of steel,
using a CNC wire-cut machine
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Planning Control

• Modern manufacturing industry consists of
  fabrication and assembly
• A plant has to
• purchase raw material or parts
• convert them into specific components
• assemble the components into the several products
• Different products could contain several common
  components

A Typical Manufacturing Plant
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Planning Control

• The information-subsystems that play a vital role
  in the smooth running of the company are
• Demand forecasting
• Operations planning
• Inventory planning and control
• Operations scheduling
• Dispatching
• Demand Forecasting
• history and the current trends
• sales data reflects its effectiveness
• Operations Planning
• development engineers look for a better
  manufacturing sequence
• the input comes from standard operation times,
  setup times
• machines and other facilities are grouped for a
  proper assembly-line operation

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Planning Control

• Inventory Planning Control
• includes parts, raw materials, assemblies,
  supplies etc.
• depicts the order quantities reorder points,
  safety stocks of raw materials, and manufacturing
  batch sizes
• Operations Scheduling
• a detailed operation sequence for individual
  activities
• start and stop times for all operations
• schedule conflicts on production facilities are
  resolved here
• Dispatching
• responsible for initializing production
• releases work orders to production operations at
  the appropriate time

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Operations Scheduling

• It is the heart of entire planning and control
  systems
• Compromises must be made between economic batch
  sizes, due dates, resource constraints, manpower
  leveling, and facility utilization
• Program evaluation review technique (PERT) charts
  are used for scheduling activities. It is a
  powerful tool
• PERT chart tell a manager
• list of operations necessary to finish a project
• time needed for each operation
• critical activities activities that consume the
  largest part of project-completion-time
• Critical path a sequence of critical activities
• Using PERT chart is also named as critical path
  method (CPM)

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Operations Scheduling

• Critical Path Method (CPM)

D, 5
5
5
2
2
G, 5
A, 6
C, 3
J, 1
F, 4
8
8
E, 3
1
7
1
7
4
4
B, 2
I, 2
H, 3
3
3
6
6
Network Diagram for CPM
A?D?G 655 16
Critical A?C?F 634
13 A?E?H?I 6332 14 B?H?I
332 8
Critical Path Analysis
Activities in a Manufacturing System