I. Product Process Analysis

Process Decomposition

The manufacturing process of a product is broken down in detail, dividing a complex production process into multiple simple operations. For instance, in automobile engine production, it can be divided into operations such as cylinder block casting, cylinder head machining, crankshaft manufacturing, and piston assembly. This helps clarify the specific operations and requirements of each operation, providing a foundation for subsequent assembly line design.

Determining the operation time for each operation is crucial for balancing the rhythm of the assembly line. Techniques such as time studies and motion analysis can be employed to accurately measure the time required for each operation. For example, on an electronics assembly line, by using stopwatch timing and motion decomposition, it is determined that installing a chip takes 30 seconds and soldering a circuit takes 45 seconds.

Process Sequence Optimization

Based on the product structure and production requirements, the sequence of operations should be reasonably determined. Some operations have sequential dependencies; for example, in furniture manufacturing, wood must be cut before dovetail joint processing can take place. Additionally, efforts should be made to minimize back-and-forth and crossovers between operations, enabling products to flow unidirectionally and continuously along the assembly line to enhance production efficiency.

II. Rhythm Setting and Balancing

Rhythm Calculation

Rhythm refers to the interval time between the consecutive production of two identical products on an assembly line. The formula for calculating rhythm is: Rhythm = Effective working time in the planning period / Product output in the planning period. For example, if a production line operates for 8 hours (480 minutes) per day and plans to produce 240 products daily, the rhythm is 480/240 = 2 minutes per product. When setting the rhythm, factors such as market demand, equipment capacity, and worker labor intensity should be comprehensively considered.

Operation Balancing

To prevent bottleneck operations on the assembly line, which can lead to low production efficiency, it is necessary to balance the operation times of each operation. By adjusting operation content, merging or splitting operations, the operation times of each operation should be made as close as possible to the rhythm time. For example, on a garment processing line, if the cutting operation takes too long, some simple cutting tasks can be allocated to the preparation stage before subsequent sewing operations to balance the operation times across operations.

III. Equipment Selection and Layout

Equipment Selection

Equipment should be selected based on the requirements of each operation. The production capacity, precision, and reliability of the equipment should match the needs of the operation. For example, in a machining line, for high-precision part processing, numerically controlled machine tools with high machining accuracy should be selected; for simple rough machining operations, ordinary machine tools can be chosen. Additionally, the maintenance costs and service life of the equipment should be considered.

The degree of automation of the equipment is also an important factor to consider. For production lines with large production volumes and high product standardization, highly automated equipment can be selected to improve production efficiency and product quality stability. For instance, in a beverage filling line, automated filling and packaging equipment can achieve high-speed and precise production.

Equipment Layout

A straight-line layout enables products to flow smoothly along the assembly line, reducing transportation time and space. For example, in a food packaging line, equipment such as raw material conveying, packaging forming, and labeling are arranged in a straight line sequentially. Products enter from one end, pass through each piece of equipment to complete packaging, and are output from the other end. This layout is simple and clear, facilitating management and operation.

For production lines with closely interconnected operations and small product sizes, a U-shaped layout can be adopted. A U-shaped layout allows workers to easily operate adjacent operations, reducing walking distances and improving work efficiency. For example, on a small electronics assembly line, workers operate on the inner side of the U-shaped line, while materials and products flow on the outer side, facilitating worker pickup and transfer.

IV. Staffing and Work Design

Determining the Number of Workers

The number of workers required for each operation is calculated based on the rhythm and operation time. For example, if the operation time for an operation is 4 minutes and the rhythm is 2 minutes, then 2 workers are needed for that operation. Additionally, workers' skill levels and work intensity should be considered to reasonably allocate work tasks.

Work Design

The work content of workers is designed to enrich and simplify tasks. Enrichment means allowing workers to participate in operations across multiple operations, enhancing their work interest and skill levels; simplification involves breaking down complex work into simple operations, making it easier for workers to master and improving work efficiency. For example, on a toy assembly line, workers can be responsible for assembling certain parts of toys within a certain period and then switch to other related assembly operations. This not only increases work interest but also improves workers' comprehensive skills.

V. Material Supply and Logistics Design

Material Supply Methods

A Just-in-Time (JIT) supply method is adopted to ensure that materials are accurately delivered to the production line when needed. A Material Requirements Planning (MRP) system can be established to precisely arrange material procurement and delivery based on production plans and inventory levels. For example, in an automobile parts production line, through the MRP system, suppliers can deliver parts to the production line side in a timely manner according to the production schedule of the automobile assembly plant.

For small-sized, high-consumption standard parts, automatic feeding devices can be used. For instance, in a mechanical assembly line, standard parts such as screws and nuts can be continuously supplied to the assembly station through automatic feeding equipment like vibratory bowls, reducing the time workers spend fetching materials.

Logistics Design

Reasonable logistics channels are designed to enable rapid and safe transportation of materials and products. Logistics channels should be wide enough to meet the passage requirements of transportation equipment (such as forklifts and pallet trucks). Additionally, logistics channels should avoid crossing with personnel channels to ensure production safety. For example, in a large home appliance production line, dedicated material transportation channels and personnel channels are set up. Materials are transported from the warehouse to the temporary storage area beside the production line by forklifts and then delivered to each workstation through conveyor belts and other equipment.

VI. Quality Control and Monitoring System Design

Setting Quality Control Points

Quality control points are set at key operations and operations prone to quality issues. For example, in a metal processing line, quality control points are set at welding and heat treatment operations, where product quality is strictly monitored through testing equipment and inspectors. The setting of quality control points should clarify inspection items, methods, and standards.

Monitoring System Design

An automated quality monitoring system is established to monitor the production process in real-time through equipment such as sensors and cameras. For example, in a glass product production line, temperature sensors are installed on melting furnaces and forming equipment to monitor temperatures in real-time. When the temperature exceeds the set range, the system automatically issues an alarm to remind workers to make adjustments. Additionally, the monitoring system can collect and analyze product quality data, providing a basis for quality improvement.