Basic Concepts and Design Techniques of GT (Group Technology)

GT (Group Technology) is a technique that aims to improve productivity by grouping similar parts with similar shapes, dimensions, and machining methods. By grouping parts, GT can rationalize process design, reduce setup time, transportation time, and waiting time between processes, and increase production quantities. This can lead to effects similar to mass production, even for small-batch production.

The basic concepts of GT are as follows:

• Pursuit of similarity: Grouping parts with similar shapes, dimensions, and machining methods.
• Rationalization of process design: Rationalizing the process design for grouped parts.
• Strengthening of inter-process linkages: Strengthening the inter-process linkages for grouped parts.

GT Design Techniques

GT design techniques can be broadly divided into shape-based design and process-based design.

• Shape-based design is a technique that performs design centered on the shape of the part. Because the shape of a part has a major impact on the machining method, optimizing the shape of a part through shape-based design can simplify the machining method and strengthen the inter-process linkages.
• Process-based design is a technique that performs design centered on the process of the part. By optimizing the process of a part through process-based design, the machining time can be shortened and productivity can be improved.

Design Based on the Pursuit of Similarity

The basic concept of GT is the pursuit of similarity. Design based on the pursuit of similarity can be performed in the following ways:

• Shape similarity: This refers to the case where the shapes of the parts are similar. Parts with similar shapes can be machined with the same process, which can simplify process design and improve productivity.
• Dimensional similarity: This refers to the case where the dimensions of the parts are similar. Parts with dimensional similarity can use the same cutting tools, which can simplify process design and improve productivity.
• Machining method similarity: This refers to the case where the machining methods of the parts are similar. Parts with machining method similarity can undergo the same processes, which can simplify process design and improve productivity.

GT is an important technique for efficiently performing small-batch production with a variety of products. The effectiveness of GT can be further maximized through design based on the pursuit of similarity.

Additional Notes

In addition to the three types of similarity mentioned above, other types of similarity can also be used for GT design. For example, material similarity can be used to group parts that are made of the same material, which can simplify the material handling process. Function similarity can be used to group parts that perform the same function, which can improve the overall functionality of the product.

By considering various types of similarity, GT designers can create more efficient and effective designs.