What is Group Technology – Definition , Advantages and Disadvantages

Definition of Group Technology:

GT can be defined as “It is the realization that many problems are similar, and that by grouping similar problems, a single solution can be found to a set of problems thus saving time and effort”

The definition of GT is although quite broad, one usually relates GT to production flow analysis only. GT can be applied in different area of production system. For component design, it is obvious that many components have a similar shape. These similar components can be grouped into design families and a new design can be created by simply modifying an existing design from the same family. By using this concept, composite components can be identified

Group technology is an approach to organising manufacture which can be applied in any industry (machining, welding, foundry, press work, forging, plastic moulding, etc.) where small-batch variety production is used. In this articles we will discuss group technology process , advantages and disadvantages , application of GT.

See Also: Flexible Manufacturing System- Types Of Flexible Manufacturing System

What is Group Technology

The basic approach enables all aspects of manufacturing, from design, through estimating and planning, to production, to be rationalised. It forms the basis for the development of computer-aided procedures and flexible automation.

Group technology is a manufacturing philosophy or principle whose basic concept is to identify and bring together related or similar parts and processes, to take advantage of the similarities which exist, during all stages of design and manufacture.

If parts can be classified into families, and machines arranged into groups, then the handling of parts during manufacture can be easily done by robot.

It must be understood that there exists relationship between finished products and the parts from which they are made. While assemblies may bear little relation to each other, the subassemblies from which they are constructed will exhibit some like features. By exploiting the similarities which exist among such a population of parts, group technology sets out to reduce the time and cost of manufacture.

The main theme is thus to identify somehow from the large variety of parts those families which require similar manufacturing operations. Cells are created to manufacture defined types and size ranges of parts.

Groups of machines, chosen for each family are situated together in a group layout, in such a way that parts flow from one machine to the next in sequence of operation. It is not-necessary for every part to visit each machine, but the machines in a cell should ideally be capable of carrying out all the operations required in the family.

It may be remembered that in a functional layout, all like machines are grouped at one place and thus a product has to move a lot of distance in a zig-zag manner. But in a cell layout, various machines are arranged so that product flows from one machine to the next in sequence.

Advantages of Group Technology:
The advantages of group technology are:

(i) Better lead times result in fast response and more reliable delivery.

(ii) Material handling is reduced considerably.

(iii) Robots can be easily used for material handling.

(iv) Better space utilisation.

(v) Smaller variety of tools, jigs and fixtures.

(vi) Improved quality and less scrap.

(vii) Output is improved due to improved resource utilisation.

(viii) Work in progress and finished stock levels are reduced.

(ix) Simplified estimating, accounting and work management.

(x) Improved plant replacement decisions.

(xi) Improved job satisfaction, morale and communication.

(xii) Reduced product design variety.

Disadvantages of Group Technology:

The disadvantages of group technology are:

(i) Additional cost of implementation of this system.

(ii) Rate of change in product range and mix.

(iii) Difficulties with out-of-cell operations.

(iv) Coexistence with non-cellular systems.

Uses of Group Technology:

Survey of product and use of group technology:

Group technology technique can be conveniently followed using a classification system. In any assembly, a variety of parts exist. These varieties of parts can be-segregated in three broad areas, viz.

(i) Standard and proprietary parts (like nuts, bolts, screws, keys, washers, etc.)

(ii) Similar parts (like shafts, gears, bearings, levers, etc.)

(iii) Product specific parts (like gear box, bed, saddle, etc.)

It may be noted that the group technology is not concerned with categories (i) and (iii) but relates to category (ii). The aim thus is to group the range of parts under category (ii) in some way, for the purpose of manufacture.

Several types of classification systems have been devised and one has to carefully consider the system based on his needs. An organisation with a wide range of products needs a complex detailed system but same is not good for the one dealing with limited range. Provision should always be made for future likely growth and classification system chosen must keep this requirement in view.