What is the best way to balance a manufacturing line? We’ll walk you through the steps to figuring out the answer.
Identify all of the steps in the process.
The first step to balancing a manufacturing line is to identify all of the steps in your process. It may be obvious that you need to start by listing all of these steps, but don’t forget about any additional ones that occur between them. For example, if you have an assembly line for a car with four main steps (frame assembly, body assembly, drivetrain installation, and paint), then there are probably several smaller tasks between them as well: engine mounting and transmission mounting for example. You can even include tasks that don’t happen every time or are only done by one person once every month or two (like replacing worn-out parts).
In addition to identifying each step as it occurs on your production line(s), also list them in order from start to finish so that when we talk about efficiency later on we’ll be able to tell where bottlenecks lie based on their sequence in the workflow of producing something.
Determine the expected time for each step.
Before you can balance your line, you need to figure out how long each step should take. This will help you identify where the bottlenecks are and how much time there is between steps. For a machine to produce one product at a time, it needs to be in one of three states: waiting for materials or parts, waiting for its operator to make their next move, or working on preparing another unit for assembly.
To calculate expected times:
- Identify all possible problems that can occur at each step of your production process and how long they’ll take (or if they’re necessary). For example, if you have an employee who changes parts while they wait in line behind someone else’s machine that has already been set up by another worker but hasn’t started yet—this causes downtime as well as increases risk since both employees are working with dangerous equipment simultaneously without proper supervision.
- Calculate how long it takes for just one person to do everything themselves without any delays or interruptions from others (this will give us our maximum throughput rate). For example: Let’s say we have 100 units per batch with each one taking four hours total including setup time plus cleanup afterward.Then 100 divided by 4 would give us 25 batches per day! That’s pretty fast considering some people only work 8 hours/day. Using these numbers let’s say we want about 1 hour per batch because we want some wiggle room too depending on what happens during production like needing extra tools etcetera…
In the manufacturing world, resources are things that your plant needs to function properly. Resources can be physical (e.g. manufacturing machinery) or intangible (e.g. human capital). In terms of a manufacturing line, there are two types of resources:
- Line capacity – the maximum amount of product that can be produced in an hour by all machines on the line (e.g., if you have 5 robots and they each produce 20 units per hour, then your total line capacity is 100 units per hour.)
- Tooling – tools like assembly jigs, fixtures, and gauges that help make sure each part is made correctly
Calculate needed man hours.
Calculating how many man hours are required for your manufacturing line is important because it determines the amount of time that you’ll need to dedicate to getting things running smoothly.
To calculate the number of man hours per week, multiply the number of operators by their average daily production rate. The result is how many days’ worth of production you can expect from each operator per week:
2 operators x 6 units per hour = 12 units per day
12 units / 5 days = 2.4 units per day
The total weekly production is equal to 2.4 (average daily production) x 7 (days worked) = 17 man-hours.
Figure out the optimum number of operators.
Once you know the critical path and have a good idea of how many operators are needed, you can figure out the optimum number of operators. The key is to balance the time it takes each operator to complete their task with the amount of time it will take for them to pass along their completed product or service to the next step in your process.
The number of operators required is dependent on where your bottlenecks are—not only in terms of time but also in terms of quantity. If one part of your production line is slower than another, this may indicate that there’s not enough manpower at that point on your line; however, if both parts move slowly due to high volume (such as when demand suddenly rises), then it’s likely that too many people are operating at once and not enough material is moving through each stage.
Keep in mind that this doesn’t apply just during rush periods: having an excess number of workers might be necessary year-round because there will always be some waiting time as one product moves through stages before others start producing again.
Calculate how much time would be spent waiting for the product.
When you’re calculating the time spent waiting for the product, it’s important to make sure that you don’t double-count. For example, if one operator spends some time waiting for parts from another department before working on their part of the line, then this should be included in your calculation of how much time is spent waiting for the product.
The amount of time should also be divided by the number of operators on the line so that this figure represents an average amount per worker. This makes it easier to compare lines or find out whether or not something needs improving to improve production efficiency.
A good understanding of the numbers can help you determine how best to balance your manufacturing line.
The first thing you need to do in creating a perfect line balancing formula is calculate the total number of man hours needed for your line. This can be done by dividing the total man hours per day by 24, which represents a full shift.
After determining how many operators you will need on your line, it’s time to figure out how many units they should produce in an hour so that they stay busy but don’t get overwhelmed. To determine this number, divide the unit rate by 90 (the standard average hourly production rate).
For example: If an operator produces 1 unit every 4 minutes and there are 10 operators on staff and they each work 8-hour shifts (48 total hours), then we would have:
- 544 units/day or 2 units per minute x 10 operators = 2080 units/day
- 2080 units/(48 x 60 minutes) = .463 units per minute or .463 parts per minute
This means that each operator needs to produce about eight parts every minute!
With this information in hand, you can now make the best decision for your plant. If there are too many operators on the line, then perhaps adding another shift might be a good idea. Or if there aren’t enough operators but the waiting time is causing bottlenecks, then perhaps adding more labor would also be helpful.