An assembly line is a production system in which a product moves through a fixed sequence of workstations, with each station completing a specific task. Computer-integrated manufacturing (CIM) is the coordinated use of computers to control and connect multiple stages of manufacturing, from design and planning to production and quality control.
How the systems work
On an assembly line, tasks are divided into repeatable operations. Materials or partially completed products move between workers, machines, or robots, allowing standardized products to be manufactured continuously at high volume.
CIM creates a connected manufacturing system. Data from computer-aided design (CAD) can be transferred to computer-aided manufacturing (CAM) equipment, such as CNC machines or industrial robots. Computers may also coordinate production scheduling, automated material handling, inventory management, process monitoring, and quality control.
Sensors collect production data and provide feedback, allowing the system to identify defects or adjust operating conditions. This integration reduces delays and errors caused by manually transferring information between separate production stages.
| Feature | Assembly line | CIM |
|---|---|---|
| Main principle | Product follows a sequence of specialized operations | Computer systems integrate and coordinate manufacturing activities |
| Typical application | High-volume, low-variety production | Automated, data-driven production requiring precise coordination |
| Main benefits | High output, consistent products, lower unit costs | Greater precision, faster information flow, reduced waste, and flexible control |
| Main limitations | Repetitive work, low customization, and disruption if one station fails | High initial cost, technical complexity, and dependence on skilled personnel |
A common misconception is that every assembly line uses CIM. An assembly line may rely mainly on human labour and simple machinery; CIM exists only when computer systems connect and control manufacturing functions. However, an automated assembly line can form part of a larger CIM system.
Exam technique
For IB Design Technology HL B4.1, define each system and explain its operation before evaluating advantages and limitations. If comparing them, emphasize that an assembly line describes the sequence of production, whereas CIM describes the digital integration and control of production processes.
