Automation Strategies

1
Automation Strategies

• Henry C. Co
• Technology and Operations Management,
• California Polytechnic and State University

2
Automation Strategies

• Specializing Operations
• Combining Operations
• Simultaneously Executing Operations
• Integrating Operations
• Reducing Setup Time
• Streamlining Material Handling
• Controlling/Optimizing Processes
• Implementing Manufacturing Database and
  Information System

3
1. Specializing Operations

• The key concept of mass production
• Low unit cost by extreme specialization of
  equipment.
• Example (automobile engine or transmission
  production)
• The plant would consists of a set of giant
  multiple-spindle machines, generally with between
  100 to 1000 tools, mainly drills, cutting
  simultaneously.
• The spindles are clustered in stations that are
  synchronously linked together mechanically via
  indexing transfer lines.

4
2. Combining Operations

• Production occurs as a sequence of operations.
  Some complicated parts may require as many as 50
  distinct steps.
• Combining operations
• To reduce the number of distinct steps by
  performing more than one operation at a given
  workstation.
• Combining operation reduces the number of setups.

5
3. Simultaneously Executing Operations

• The strategy is to perform multiple operations at
  the same workstations simultaneously.
  Multi-spindle machining center utilize this
  concept.

6
4. Integrating Operations

• A series of workstations are linked together as a
  single integrated mechanism by automatic work
  handling devices.
• To achieve high rates of production, dial
  indexing machines, trunnion machines, and
  transfer lines have been designed to perform a
  great variety of many different metal-cutting
  processes.
• For example, the rotary indexing machine performs
  a sequence of machining operations on several
  work-parts simultaneously.
• Radial machining heads are located around the
  periphery of a horizontal circular table or dial.
  Parts are fixtured on the table and indexed
  between successive stations.

7
5. Reducing Setup Time

• Whereas the strategy of combined operation
  reduces the number of setups, this strategy is
  concerned with reducing the setup time. This is
  accomplished by Group Technology (e.g.,
  scheduling of similar parts through the
  production machine, use of common fixtures for
  different but similar parts) and designing
  greater flexibility into the manufacturing
  system.
• Reduce setup time means lower economic quantity
  (smaller lot sizes). Reduced lot sizes means
  lower work-in-process inventory and faster
  turnaround time.

8

• The hydraulic-valve division of Parker-Hannifin
  Corporation recently installed a flexible
  manufacturing cell (FMC) at its Forest City,
  North Carolina plant.
• The FMC consists of a twin-spindle CNC turning
  center, an angle-elongate hole mill, a wash
  station, and a gantry robot to handle the work
  piece through the cell. This cell is used to
  produce a specific family of hydraulic valves.
• Prior to the FMC, the valves were manufactured
  using a number of ACME six spindle bar machines
  and Kingsbury center column machines (a type of
  dial indexing machines), which involved up to 54
  setup hours and a large number of work-in-process
  (WIP) inventory.
• The FMC was installed to reduce product lead
  time, inventory cost, scrap, and indirect labor
  cost and to improve quality. Setup time along
  was reduced to two hours and WIP inventory to
  zero.

9
6. Streamlining Material Handling

• A great opportunity for reducing nonproductive
  time exists through the use of mechanized and
  automated materials handling methods. The typical
  benefits of improved handling are reduced
  work-in-process and shorter throughput times.
  These benefits are generally achieved by
  minimizing the distances over which the
  work-parts must be moved, providing for smooth
  flow through adjacent stations, handling the
  parts in larger unit loads, and other common
  sense principles.

10

• The Harris Corporation in Kennedale, Texas has
  one of the most sophisticated flexible
  manufacturing systems in existence.
• Utilizing the group technology concept, Harris
  has logically grouped together in one area, the
  machines that perform most of the necessary
  manufacturing operations required for similar
  families of parts.
• Cylindrical print rolls, are automatically loaded
  by a robot into a double-end machining station,
  where both ends of the roll are machined
  simultaneously.
• When this machining operation has been completed,
  the robot removes the work piece, and replaces it
  on the carrier of a car track system.

11

• After all work pieces on the carrier have been
  machined, the carrier is directed to a robot
  serviced, numerically controlled lathe station.
• These standard carriers transport over 600
  different parts which can be manufactured in the
  system. Precise carrier positioning of the car
  track system enables robots to perform
  consistently. Again the robot removes a roll from
  the carrier and places into one of the two
  available NC lathes. These robots are programmed
  with a flexibility to handle each of the
  different part sizes that are manufactured in the
  system.
• When the lathe operations have been completed for
  all of the rolls on the carrier, the carrier is
  directed throughout the remainder of its
  manufacturing operations, and then to inspection
  and shipping areas.
• Work-in-process storage stations of the car track
  systems are strategically integrated throughout
  the manufacturing area to ensure rapid work piece
  delivery and maximum production efficiency.

12
7. Controlling/Optimizing Processes

• On the factory floor, CAM systems perform machine
  monitoring and adjustments as well as controlled
  materials movement. Process control includes
  conventional analog feedback control or computer
  control, which allows more flexibility in the
  type of control exercised over the process.
  Control strategies that can be implemented by
  computer include optimal control, feedback
  control, sequencing control, and adaptive
  control.

13
8. Implementing Manufacturing Database
Information System

• Development of a manufacturing database and
  information system is an essential function in
  manufacturing. The manufacturing database
  include
• Part drawings, material specifications, and bills
  of materials (from design engineering)
• Route sheets which specify the process plans for
  the parts, tool lists for the route sheets, tool
  inventory record (from manufacturing
  engineering)
• Methods description, time standards, equipment
  justification document (from industrial
  engineering)
• Master schedules, production schedules, exception
  report (from production planning and control)
• Inventory records (from inventory control and
  shipping).

14

• CAD/CAM stands for Computer-Aided Design (CAD)
  and Computer-Aided Manufacturing (CAM). A CAD/CAM
  system generates a common data base which can be
  augmented, modified, used, and distributed over
  networks of terminals and computers. The data
  generated in the CAD design process is used in
  CAM to generate machine instructions for parts
  manufacturing.
• Major advantages can be realized by integrating
  information and sharing the information among the
  various organizations, thereby reducing the
  needless duplication of information and of the
  activities necessary to generate it.

15

• For example, at the K-2 Ski Company of Kent,
  Washington, the use of CAD/CAM has helped them
  build an extensive data base that is available
  for reference and review at all times by their
  designers and consulting experts.
• Their computer-aided manufacturing program helps
  them produce top quality tooling, dies, and
  fixtures on sight, providing the precision
  quality they require and the assured delivery
  schedule they need. And throughout the assembly
  process, bar code readers provide computer input
  on production flow and material requirements to
  their MRP (material requirements planning)
  system.
• This combination of a CAD/CAM and MRP system
  helps K-2 shorten the development and production
  time of new products. It also allows them to take
  advantage of the knowledge gained in previous
  designs and programs to constantly improve their
  products and maintain their competitive position
  in the rapidly growing leisure products and
  sports equipment field.