GT(group technology) Basic Concepts, Design Techniques, and Design Based on Similarity

GT Basic Concepts

GT is a technique that groups parts with similar shapes, dimensions, and machining methods to rationalize process design. By using the appropriate machines and tools for each group, it can reduce the preparation time of work, the transportation time between processes, and the waiting time for machining. It can also increase the processing quantity compared to when it is produced disorderly, and obtain an effect close to mass production, thereby improving productivity.

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 inter-process linkages for grouped parts.

GT Design Techniques

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

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

Design Based on Similarity

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

• Shape similarity

Shape similarity refers to the case where the shape of the part is similar. Parts with shape similarity can be machined with the same process, so the process design can be simplified and productivity can be improved.

• Dimension similarity

Dimension similarity refers to the case where the dimensions of the part are similar. Parts with dimension similarity can use the same tools, so the process design can be simplified and productivity can be improved.

• Machining method similarity

Machining method similarity refers to the case where the machining method of the part is similar. Parts with machining method similarity can undergo the same process, so the process design can be simplified and productivity can be improved.

GT is an important technique for efficiently performing small-batch production of a variety of products. The effect of GT can be further maximized by designing based on similarity.

Additional Explanations

• The benefits of GT include the following:
  • Reduced preparation time, transportation time, and waiting time
  • Increased processing quantity
  • Improved productivity
• GT is used in a variety of industries, including:
  • Manufacturing
  • Construction
  • Automotive
  • Aerospace