a line assembly strategy that aims to produce a particular product within a particular time frame.
How Line Balancing Works
When a company puts a line balancing strategy in effect, they are distributing work and labor in a way that will meet the company’s desired production rate with little idle time. Outside of meeting production goals efficiently, line balancing offers other benefits:
- Creates a streamlined assembly process.
- It can potentially create a healthier workplace as the factory has distributed work evenly among its employees, with little overlap between workstations.
- Improves quality of output.
- Reduces waste.
- Uses employees to their fullest extent.
For line balancing to be successful, a factory should have, in theory, designated workstations and a layout conducive to linear workstation flow. Workstations are any station in which an employee or employees perform a set of tasks on a product. Best practice dictates that a company should also follow specific steps to implement the strategy. These steps are:
- Break down the production process into steps. By drawing a precedence diagram, a visualization of this sequence, managers can better see the specific tasks within the course of manufacturing a product.
- Next, the company needs to perform time studies. Time studies determine the maximum amount of time an employee takes to complete a task at a workstation.
- Then, by dividing the actual task time/desired task time, you can see how many workstations you’ll need.
- A company will assign labor at each workstation until they’ve evenly distributed workers. Ideally, each workstation will handle the same amount for the same amount of time. Companies will also evenly distribute work among line workers.
- Calculating Takt time helps a company determine how they distribute the workload. The formula for this is total available production time/customer demand=Takt time.
- The proof is in the pudding! Test your line balancing.
Example of Line Balancing
A small company produces specialty hard candy in bulk, but management is finding that the factory is not hitting its numbers. The factory should be producing 200 large boxes a day. The foreman decides to balance the production line. First, she breaks down the steps the factory takes to make a single piece of candy. Because the company uses machinery for mixing candy ingredients and wrapping the individual candies, she decides to focus on manual labor: breaking the candy from the molds and filling and labeling the boxes.
Breaking all the candy from the molds should take no more than 60 minutes, but it is taking 120 minutes. The foreman divides 120/60 to see that she needs two workstations to accomplish this task in the desired timeframe. She now turns her attention to filling and labeling boxes. She discovers that this workstation is dreadfully understaffed. What should be taking a team 3 minutes per box is taking 12 minutes. The foreman needs 4 workstations to accomplish the ideal time.
Looking at her employees, she sees that she has 20 employees on quality control, 5 on molds, and only 2 on the packaging. Because quality control is overperforming, she reassigns 5 employees to molds and 5 to packaging. After testing her line balance, the factory is now hitting the numbers it needs to make.