Group Technology | Definition , Meaning , Advantages
What is Group Technology
Group technology (GT) is a concept that is currently attracting a lot of attention from the manufacturing community. GT offers a number of ways to improve productivity in the batch manufacturing. The essence of GT is to capitalize on similarities on recurring tasks. GT is, very simply, a philosophy to exploit similarities and achieve efficiencies grouping like problems.
Definition of GT
“Group technology is the realization that many problems are similar and that, by grouping similar problems, single solution can be found to a set of problems, thus saving time and effort”
History of GT
Prior to 1913, the era of Henry Ford and his model T, all machining models were similar to our present job shop techniques with machines laid out usually in lines or blocks of similar machines. The work was loaded onto the machines usually by the manual progress control system. Ford introduced the assembly line and that, in turn, led to automated transfer machines. However, the majority of engineering do not produce items in quantity that justify such methods and so the jobbing shop philosophy continued. GT is mainly a coordination of
normal good engineering practices. It is impossible to say who first practiced GT.
There are reports of it having been used in Germany in the 1930s. In an international Conference held in Stockholm in 1947, the basic groups were explained by C.B.Nanthorst. In Italy M. Patrignany was an early exponent of this technology. However, little of this appears to have been in English. First published work was from the USSR by S.P.Mitrofanov in 1959 and there after subsequent books were published by F.S.Denyanyuk and E.K. Ivanov.The first reported work on GT outside Russia was done by a French Forges et Ateliers de Construction Electriques de Jeurmont – and this was about in Machinery in 1962. Subsequently, several British companies conducted considerable work in this field. There have also been considerable studies done by various consultants in the Universities. The significant contribution by J.L.Burbidge in the 1 960s led to GT as A total Manufacturing Philosophy.
Advantages of GT
According to Burbidge, following are the advantages after introducing GT in manufacturing.
a. Short throughput times because machines are closed together.
b. Better quality because groups complete parts and the machines are closed together under one foreman.
c. Lower material handling costs because machines are closed together under one foreman.
d. Better accountability because machines complete parts. The foreman can be made responsible for costs, quality, and completion by due date.
e. Training for promotion for promotion since GT provides a line of succession, because a group is a mini-department.
f. Automation GT is a first evolutionary step in automation.
g. Reduced set up time since similar parts brought together on the same
h. Morale and job satisfaction since most workers prefer to work in groups. Studies undertaken by N.L.Hyer indicate the following significant savings after implementing GT Snead prepared a summary matrix, listing the benefits listing benefits achieved for the various GT.
Group Technology in CIM
One may question whether a cellular concept is applicable to CIM systems. Some studies have shown that grouping machines to machine cells may limit the manufacturing system flexibility. However, industrial applications have proven that it is virtually impossible to implement a large scale CIM subsystem using a cellular concept. Here after, the automated manufacturing systems that cellular approach can be called as, Cellular Automated Manufacturing (CAMS).
Four crucial factors of CAMS as identified by Kusiak are:
1. Volume of information
Volume of information a large-scale CIM subsystem is typically large, and it is too expensive to effectively process information without the system’s decomposition.
2. Material handling system
In a typical CIM subsystem, automated material handling carriers are used (AGVs and Robots). Each of the two carriers can tend a limited number of machines.
3. Technology Requirement
Some machines have to be grouped together due to technological requirements. For example, a forging machine and a heat treatment section.
Although in most of the currently CIM subsystems, the degree of automation is higher than in classical manufacturing systems, humans will be, for a long time, an integral CAMS is easier to manage than the entire system.
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