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Line balancing is a flow-oriented production strategy for improving productivity and cost-efficiency in mass production processes. An optimal time frame is designated for the production of a particular product. Tasks are then equally distributed among workers and workstations to ensure that each operation in the line happens within the specified time frame.

What is Line Balancing?

In a nutshell, production line balancing is simply the assignment of the right number of workers and machines to each assembly line segment. This helps meet production rate targets with minimal idle time.

The Benefits of Production Line Balancing

Production line balancing is an excellent model for attaining improved efficiency in the production process. Some of its benefits are:

  • Reduces the amount of idle time in work stations
  • Facilitates a streamlined flow of  the production process
  • It helps to create the right number of workstations and the number of operations to have in each station.
  • Achieves high employee morale and camaraderie by consolidating processes
  • Improves the rate of production and the output quality of the produced items
  • Maximizes workforce utilization  and production capacity  
  • Reduces wastage

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How to Do Line Balancing

In order to achieve the aforementioned benefits, your production line must be structured in a manner that supports a streamlined flow of materials and parts from one workstation to another. 

A workstation refers to any point on the assembly line where operators execute a task on the manufactured piece. The cycle time is the time it takes to complete each workstation task. An ideal production rate is where each product is produced within the set time frame.

Experts concur that attaining optimal scheduling is a near-impossible task. Manual calculations can often be lengthy and laborious. The processing time at each work station should be balanced. 

Several heuristic computer programs exist to help hasten the line balancing process in food and beverage companies. IFS stands out as the fastest line balancing software, with the agility to adjust based on machine/workers’ throughput.

Steps in Assembly Line Balancing

 

1. Outline your workstation sequence and draw a precedence diagram

This process involves breaking the whole production process into sequential stages.  A product cannot proceed from one segment to the next unless the task in a given workstation is complete. 

A precedence diagram is a tabular representation of the tasks in the course of a production project. You can create overall or partial precedence diagrams that show the whole or a specific section of the project. Your chart should detail the production processes, events, and the dependencies between the two.

2. Estimate the needed cycle time for each workstation

You will need to perform time studies to find out the duration it takes to complete each task in the production line. The cycle time is the maximum duration a job takes for completion at each workstation. 

You can arrive at this exact figure by dividing the required product units by the production time available in a day. That gives you the time (in minutes) between each workstation at the current machine rate and workforce.

Cycle time computation considers the total number of units produced per day in a single line. When the same product is made in multiple lines, composite cycle time calculations would need to be done on digitized line balancing tools for accuracy.

 

3. Calculate the hypothetical number of workstations you will need

 

This calculation will help to attain a balanced task distribution in each of the workstations based on the cycle times. You can arrive at the number of workstations you need by dividing the sum of your task times by the desired actual times. 

Algorithmic calculations through P-graph frameworks on a line balancing software are often more reliable in this case. They take into consideration multi-period operations, machine/employee performance, and redundancies. For manual calculations, the formula is given by:

 

4. Start assigning tasks to the workstations until the process times are equal 

 

Proceed to rearrange the tasks in a way that reduces excess capacity and production bottlenecks. 

That involves redistributing the number of workers from stations of minimal workloads to stations of excess workloads. This process helps to reduce the waiting times in stations of excess capacity.

Try to share the amount of work between the number of operators in a line logically, aiming to maximize machine utilization. The idea is to have each task taking the same amount of time for synchronicity.

Note that for efficiency in meeting customer demand, you will need to carry out Takt time calculations to inform your distribution of workloads.

The Takt time is a measure of the time a competent worker or an unmanned machine takes to perform a task. If you perform keg line balancing to the point that production exceeds takt time, you run the risk of overproduction and wastage. However, producing slower than takt time can lead to delays, idle time, and frustrated clients.

 

5. Test the efficiency of your assembly line

 

After a balanced task distribution, the next step is testing the effectiveness of the undertaking. Testing can help to reveal further areas that need efficiency improvements and rebalancing.  The assembly line efficiency formula is given by:

If you need further rebalancing, you can adjust parameters such as machine times, Takt Time time, and set up time. 

For instance, by improving machine time through balanced upgrades and the training of workers, you can significantly reduce the cycle time. Resizing line segments (increasing or reducing the number of workstations in each division) can also reduce the overall work time and contribute to a lean manufacturing approach.

The bottom line

Assembly line balancing is the process of optimizing workflow and production efficiency. It is achieved through an equal task distribution based on machine and workers’ proficiency. It is purely an analytical undertaking that you can uncomplicate by using a smart set of line balancing software.

Enterprise resource planning software such as IFS can help balance production lines as the calculations and processes are automated and configured from the get-go. These are particularly useful in industries such as food and beverage. If you’re interested in production line balancing for your business, contact the Corning Data team for more information.