An investigation into the application of group technology in advanced manufacturing systems

1
An investigation into the application of group
technology in advanced manufacturing systems

• Presented by
• Yasar Levent Koçaga

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Group Technology

• A manuf. philosophy in which similar parts are
  identified and grouped together to take advantage
  of their similarities in design and manuf.
• A concept to increase prodn efficieny by
  grouping various parts and products with similar
  design and/or production processes

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Group Technology

• A theory of management based on the principle
  that similar things should be done similarly.
• These similar things include
• product design
• process planning
• fabrication
• assembly
• production control

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Benefits of GT

• Product design
• Tooling and setups
• Material handling
• Prodn and inventory control
• Process planning
• Employee satisfaction

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GT Planning

• Coding
• specification of knowledge concerning the
  similarities between parts
• Classification (group formation)
• The use of part codes and other information to
  assign parts to families
• Layout
• Physical placement of machines on the shop floor

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Coding structures

• Monocodes (hierarchical)
• Polycodes (chain-type)
• Mixed-codes

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Layout

• GT can be viewed as an attempt to obtain the
  advantages of flow line systems in environments
  previously ruled by job shop procedures
• Thus 3 types of group layout arise
• GT flowline
• GT cell
• GT center

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Literature review

• Most of the research available deals with GT
  models and techniques
• Very little attention given to practical issues
  and GT applications

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Literature review

• Design-oriented approaches
• Visiual inspection
• Part coding and classification analysis (PCA)
  

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Literature review

• Production-oriented approaches
• Array based methods
• Hierarchical and non-hierarchical methods
• Heuristics
• Mathematical programming models

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Literature review

• GT clustering methods
• Sequential decision making processes
• Mathematical programming models
• Simulation
• Network theory
• Fuzzy theory
• Heuristics
• AI and expert systems

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Literature review

• GT clustering methods dominate
• Clustering methods do not consider many
  operational and technological constraints as
  copmpared to MP
• MP limited to problem size

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Literature review

• Many subjective factors from realistic situations
  not included anyway
• Simulational models, fuzzy theory, AI and expert
  systems offered for realistic constraints
• Nevertheless, human factors, behavioral and
  managerial issues

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Some applications

• NTI
• Deere Co.
• Both cases point out to the benefits of GT if
  well applied

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Scope of GT in advanced manufacturing systems

• GT facilitates JIT which requires
• Simple prodn line with kanban material flow
• Setup reduction
• Elemination of all waste from WIP to scrap and
  rework
• U-shaped layout

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Scope of GT in advanced manufacturing systems

• Process similarity and product flexibility when
  designing cells for FMS
• AGVs must also be considered
• Interactions between cells must be considered
• OPT can be used to eleminate bottleneck
  operations in JIT and FMS.

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Further research

• Reducing the gap between theory and practice is
  crucial
• Comparison of current cell formation procedures
• Accurate similarity measures
• Techniques that consider batch size, processing
  and setup time when selecting parts
• Aspects such as capacity integration between
  various machines in resource grouping

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Further research

• Aspect of grouping workers
• Other associated resources such as tools, jugs,
  ixtures and pallets when grouping parts and
  machines
• Models to find the optimum flexibility when
  designing FMS cells
• Application of recent technologies such as AI