CBAC

• Process selection


  Deciding on the way production of goods or services will be organized
• Make or buy decision


  • Considerations include: Available capacity, Expertise, Quality considerations, Nature of demand – high and steady vs. low and seasonal, Cost
• Process types


  • Projects - Special case – non routine job
  • Job shop - Small scale
  • Batch - Moderate volume
  • Repetitive/assembly line - High volumes of standardized goods or services
  • Continuous - Very high volumes of non-discrete goods
• Automation


  The substitution of machinery for human labor. Involves sensing and control devices that enables it to operate
• Levels of automation


  • Fixed automation
  • Programmable automation
• Computer Aided Manufacturing


  Use of computers in process control, replacing human functions with machine functions
• Numerically Controlled Machines


  Machines that perform operations by following mathematical processing instructions
• Types of Numerically Controlled Machines


  • Computerized Numerical Control (CNC)
  • Direct Numerical Control (DNC)
• Components of a Robot


  • Mechanical Arm
  • Power supply
  • Controller
• Flexible manufacturing system


  • Group of machines designed to handle intermittent processing requirements and produce a variety of similar products. Re-programmable controllers, Can handle intermittent requirements, Flexibility with lower capital requirement as opposed to "hard automation", Can handle quick changeover time, But only applicable to family of similar parts
• Computer Integrated Manufacturing


  System of linking a broad range of manufacturing activities, through an integrating computer system. Can link operations of other FMS towards one synchronized whole. Integrates information from other parts of the organization to manufacturing
• Facilities layout


  The configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system
• Importance of layout decisions

  • Requires substantial investments of money and effort, Involves long-term commitments, Has significant impact on cost and efficiency of short-term operations
• Reasons for layout decisions


  • Inefficient operations
  • Changes in the design of products or services
  • The introduction of new products or services
  • Accidents / Safety Hazards
  • Changes in environmental or other legal requirements
  • Changes in volume of output or mix of products
  • Changes in methods and equipment
  • Morale problems
• Basic layout types


  • Product layouts
  • Process layouts
  • Fixed-Position layout
  • Combination layouts
• Product layout


  Layout that uses standardized processing operations to achieve smooth, rapid, high-volume flow
• Types of product layout


  • Product Line – Standardized layout arranged according to a fixed sequence of production tasks
  • Assembly Line – Standardized layout arranged according to a fixed sequence of assembly tasks

  
• Advantages of product layout


  • High rate of output
  • Low unit cost
  • Labor specialization
  • Low material handling cost
  • High utilization of labor and equipment
  • Established routing and scheduling
  • Routing accounting and purchasing
• Disadvantages of product layout


  • Creates dull, repetitive jobs
  • Poorly skilled workers may not maintain equipment or quality of output
  • Fairly inflexible to changes in volume
  • Highly susceptible to shutdowns
  • Needs preventive maintenance
  • Individual incentive plans are impractical
• Process layout


  Layouts that can handle varied processing requirements
• Advantages of process layout


  • Can handle a variety of processing requirements
  • Not particularly vulnerable to equipment failures
  • Equipment used is less costly
  • Possible to use individual incentive plans
• Disadvantages of process layout


  • In-process inventory costs can be high
  • Challenging routing and scheduling
  • Equipment utilization rates are low
  • Material handling slow and inefficient
  • Complexities often reduce span of supervision
  • Special attention for each product or customer
  • Accounting and purchasing are more involved
• Fixed-position layout


  Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed
• Cellular layout


  Layout in which machines are grouped into a cell that can process items that have similar processing requirements
• Cellular manufacturing


  • Better human relations - Cells consist of a few workers who form a small work team; a team turns out complete units of work
  • Improved operator expertise - Workers see only a limited number of different parts in a finite production cycle, so repetition means quick learning
  • Less in-process inventory and material handling - A cell combines several production stages, so fewer parts travel through the shop
  • Faster production setup - Fewer jobs mean reduced tooling and hence faster tooling changes
• Group technology


  The grouping into part families of items with similar design or manufacturing characteristics
• Primary methods for accomplishing conversion to GT and cellular manufacturing


  • Visual Inspection
  • Examination of Design and Production
  • Production Flow Analysis (Manufacturing perspective)
• Line balancing


  The process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements
• Precedence diagram


  Tool used in line balancing to display elemental tasks and sequence requirements
• Cycle time


  The maximum time allowed at each workstation to complete its set of tasks on a unit