An investigation into the application of group technology in advanced manufacturing systems Presented by: Yaşar Levent Koçağa

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 prod’n efficieny by grouping various parts and products with similar design and/or production processes

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

Benefits of GT Product design Tooling and setups Material handling Prod’n and inventory control Process planning Employee satisfaction

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

Coding structures Monocodes (hierarchical) Polycodes (chain-type) Mixed-codes

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

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

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

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

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

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

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

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

Scope of GT in advanced manufacturing systems GT facilitates JIT which requires:  Simple prod’n line with kanban material flow  Setup reduction  Elemination of all waste from WIP to scrap and rework  U-shaped layout

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.

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

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