A flexible production line is a type of production line that is composed of multiple adjustable machine tools, mostly specialized machine tools, along with automatic transportation devices.
The flexible production line operates through computer management and incorporates multiple production methods to minimize production costs and maximize efficiency.
With the advancement of science and technology, society’s expectations for the functions and quality of products are increasing, and the cycle for product renewal is becoming shorter and more complex. This presents a challenge to traditional mass production methods.
This challenge affects not only small and medium-sized enterprises (SMEs), but also large and medium-sized state-owned enterprises. In mass production modes, flexibility and productivity are often in conflict. As we know, economies of scale can only be achieved with single-species, large-batch, equipment-specific, stable processing, and high efficiency. On the other hand, multi-variety and small-batch production, with low equipment specificity, often results in frequent fixture adjustments, difficulty in maintaining process stability, and a decrease in production efficiency.
To improve the flexibility and efficiency of manufacturing while ensuring product quality, reducing production cycle times, and lowering product costs, flexible automation systems have been developed. This allows small and medium-sized batch production to compete with mass production.
Flexible automation began to be put into practical use in production in the early 1970s, starting from the first digitally controlled milling machine at the Massachusetts Institute of Technology in 1954. Over the decades, flexible automation has rapidly evolved from the application of a single CNC machine tool, to the machining center, flexible manufacturing unit, flexible production line, and computer integrated manufacturing system.
In the context of flexible production lines for machinery manufacturing, the basic components are:
Automatic processing system
An automatic processing system is a system that focuses on processing similar parts with the same dimensions (although the shapes may not be identical), similar weights, made of the same material, using one or several CNC machine tools or specialized machine tools.
The logistics system is an integral part of a flexible production line, composed of various transportation devices such as conveyor belts, track-turntables, and robots, responsible for supplying and transporting workpieces, tools, etc.
The information system is a critical component of a flexible production line, responsible for collecting, processing, and providing feedback for various information needed during processing and transportation. It also controls machine tools or transportation equipment at different levels through electronic computers or other control devices such as hydraulic or pneumatic devices.
Software systems play a crucial role in effectively managing flexible production lines using electronic computers.
These systems encompass software for design, planning, production control, and system supervision.
Flexible production lines are ideal for small and medium-sized batch production, with an annual output ranging from 1000 to 100,000 pieces.
A flexible production line is a highly automated and technologically complex system that combines microelectronics, computer science, and systems engineering to address the challenge of balancing high automation and high flexibility in mechanical manufacturing.
Some of the key advantages of a flexible production line include:
- High Equipment Utilization: A group of machine tools programmed into a flexible production line has a significantly higher output compared to the same group of machine tools operating independently.
- Reduced Work-In-Process: The number of products in the production process is reduced by approximately 80%.
- Stable Production Capacity: The automatic machining system, which includes one or more machine tools, has the ability to downgrade in the event of a failure and the material handling system can bypass a faulty machine.
- High Product Quality: Parts are processed with high precision and stable processing methods, as loading and unloading is done only once.
- Flexible Operation: Some flexible production lines can be maintained, loaded, and inspected during the first shift, allowing for normal production during the second and third shifts without additional supervision. The monitoring system can also handle unexpected issues such as tool wear or material blockages.
- Large Production Capacity: The tools, fixtures, and material transport devices are adjustable, and the system layout is designed to allow for the addition or subtraction of equipment as needed to meet market demands.
The development of flexible production lines is driven by two main trends:
- Integration with Computer-Aided Design and Manufacturing Support Systems: By using typical process data from the original product series, various modular flexible systems are formed with both material and information flow, combining different modules.
- Automation of the Entire Production Process: The automation of the entire production process from product decision-making and design to production and sales is a growing trend, especially with the implementation of computer-integrated manufacturing systems. In this larger system, the flexible production line is just one component.
Type of flexible production line
Flexible production lines can be divided into several categories based on:
- Size: They can be classified as product production lines and parts production lines.
- Rhythm: They can be divided into production lines and non-flow production lines.
- Automation Levels: They can be categorized as automated production lines and non-automated production lines.