Businesses are constantly juggling waste reduction, improving profitability, and reducing downtime because these are crucial for product quality and boosting efficiency. Fortunately, there are ways to implement these goals smartly.
One-piece flow or Continuous Flow is a lean manufacturing tool that focuses on working on one single unit at a designated time in one go without interruption.
This ideal manufacturing tool benefits large setups and small manufacturing facilities equally.
What is One Piece Flow?
One Piece Flow is a production method in lean manufacturing. The core concept involves manufacturing goods through continuous steps with no downtime and Work-in-Progress. Also known as “continuous flow” or single-piece flow, this concept strongly aligns with Just in time or JIT.
One-piece flow involves setting up workstations to facilitate production in one go. Such a setup ensures that product manufacturing flows continuously while focusing on one product at a time until it is manufactured.
One-Piece Flow vs. Batch Production Flow
Batch production and one-piece flow represent two distinct approaches to manufacturing. Let’s dissect each concept to see how it differs from the other.
| Batch Production | Continuous Flow |
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Working of One Piece Flow
An example is the best way to understand how one-piece flow is superior to traditional batch production. Let’s examine it.
Scenario
Consider manufacturing ProductX, which will have to go through four steps until completion,
Traditional Batch System
In this case, each worker handles the same step for 10 units of ProductX before moving onto the next stage.
For example, worker 1 might complete step 11 on ten units of ProductX before passing them all to worker 2.
Worker 2 would then perform step 2 on those 10 units, and so on.
Points to Ponder
While this system might seem efficient at first, it later introduces inefficiencies such as:
- Units might get delayed waiting for others to catch up. This slows down the entire process.
- A defect in one unit would affect or delay the entire batch.
- Managing multiple units at once increases the likelihood of errors.
One Piece Flow
On the contrary, in one one-piece flow, each worker focuses on a single unit of Product X at a time.
Assume worker 1 completes step 1 on the first unit and immediately hands it off to worker 2 for step 2.
After performing his task, worker 2 passes the product to worker 3, and so on.
Result? There are no delays and a consistent and steady production pace.
Comparing Time to Completion Through Example
Now, we’ll compare the time Product X takes to complete in both scenarios with the assumption that each step takes 1.5 minutes per unit.
Batch Processing
| Step 1 | Worker 1 completes step 1 for 10 units in 15 minutes. |
| Step 2 | Worker 2 completes step 2 for 10 units in another 15 minutes. |
| Step 3 | Worker 3 completes step 3 for 10 units in 15 minutes. |
| Step 4 | Worker 4 completes step 4 for ten units in 15 minutes. |
Total Time to complete one unit: 1 hour
Total time to complete the batch: 1 hour
One Piece Flow
| Step 1 | Worker 1 completes step 1 for the first unit in 1.5 minutes and hands it over to worker 2. |
| Step 2 | Worker 2 completes step 2 for that unit in 1.5 minutes and passes it to worker 3. |
| Step 3 | Worker 3 completes step 3 for that unit in 1.5 minutes and passes it to worker 4. |
| Step 4 | Worker 4 completes step 2 for that unit in 1.5 minutes. |
Total time to complete one unit: 6 minutes
Total time to complete 10 units: 1 hour
Getting Started with One Piece Flow
Here’s the strategy to implement if you wonder how to start a piece flow.
Assess Your Current Production System
- Create a value stream map to identify bottlenecks and waste.
- Ensure the production process is not overly complex and is balanced.
Invest in the Right Equipment and Resources
- Acquire tools like conveyor belts, storage bins, and barcode scanners.
- Ensure adequate factory space; if not enough, expand.
Train Your Workers
- Educate workers on the principles of One Piece Flow.
- Provide entry level training on lean manufacturing and Just in time
- Train your workforce on new equipment and processes.
Implement Changes Slowly
- Start with a smaller area of your manufacturing unit.
- Go for gradual expansion, more elaborately, when the system runs smoothly.
Monitor and Adjust as Needed
- Regularly review the production process.
- Keep improving the processes, equipment, and workflows regularly.
Cellular Layout: Empowering One Piece Flow
Conjugating one-piece flow with cellular layout works as a brilliant strategy to ensure production efficiency. Cellular layout refers to the installation where all the machinery and required setup for completing a particular production process in one flow exists. In simpler words, it’s about setting up the entire production system in the order of production.
Advantages of One-Piece Flow
Faster Production Times
One-piece flow speeds up the production process by avoiding downtime and eliminating unnecessary WIP. This streamlined approach thus helps manufacturers in many ways:
- It cuts the time needed to complete products.
- Helps reduce production costs.
- Quicker processing = quicker response.
- Manufacturers can adapt faster to customer demands and market changes.
Less Inventory, More Space
By implementing a one-piece flow, the company only produces what’s needed or what has been ordered, nothing less or more!
As a result, manufacturers get lots of valuable floor or warehouse space for free. It also eliminates the need to store excessive stock. The end result is overall efficiency!
Prompt Error Detection
Identifying errors becomes much easier when focusing on one product at a time. If an issue occurs, it’s contained to that single item, making rectification easier before it gets bigger.
In a broader picture, if we compare it to the volume production batch, the whole batch will be affected if a defect exists. Also, the faults first go unnoticed, and when they’re spotted, they’ve already affected the entire batch.
Shorter Lead Times
One-piece flow is all about one product at a time, quicker response, and shorter lead times. This system helps get products into your customers’ hands more quickly. Faster delivery equals happier customers — plain and simple!
Top Quality Products
The one-piece flow essentially transforms every worker into a quality control expert. Workers can instantly catch and address issues at the workstation before the product moves to the next step.
This hands-on approach naturally leads to better craftsmanship and higher-quality results.
Less Waste
Less waste means leaner, more efficient operation. One-piece flow eliminates overproduction, which is the primary source of waste in batch production. It also:
- capital time
- unstable inventor
- cuts down on wasted labor
Safer Work Environment
Clutter reduction is a bonus of a one-piece workflow. With fewer materials flying around, there’s less risk of accidents, creating a safer workspace for everyone.
Boosted team Morale
This system encourages employee involvement, especially in problem-solving. Workers are encouraged to stay engaged, contribute ideas, and take pride in catching and fixing issues proactively.
This sort of teamwork goes a long way in building a positive and motivated workplace.
Numbers Do the Talking — Statistics and Figures
- According to a study, the implementation of one one-piece flow resulted in the following:
- 50% manufacturing cycle time reduction
- 70% improvement in productivity
- 30% less usage of the inventory space
- A case study from Sekine’s book shows how the implementation of one-piece flow by oriental Motor helped them achieve faster delivery times and reduced waste.
Concepts Often Confused with One-Piece Flow
Is Continuous Flow the Same as Just-in-Time (JIT)?
No! They are not the same, but they complement each other in lean manufacturing. JIT emphasizes system-wide waste reduction while continuous flow streamlines individual tasks. Together, they create a leaner, more responsive manufacturing process.
| Just-in-Time | Continuous Flow |
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Isn’t Continuous Flow the Same as Batch Processing?
Not at all! This is another misconception, so let’s decode it.
| Batch Processing | Continuous Flow |
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One Piece Flow Challenges
Like every other lean tool, one-piece flow also has its own set of cons.
- It requires high levels of coordination. In order to make it work perfectly, all workers and processes must be seamlessly synchronized. Achieving this level of coordination is challenging, particularly with large setups and complex operations.
- One-piece flow comes with a higher setup cost, requiring specialized equipment and resource investment. Small setups with limited budgets find it impractical.
- One-piece flow isn’t suitable for every production scenario. In cases where product designs are stable and unlikely to change, a traditional batch system might be more cost-effective.
- Maintaining the benefits of a one-piece flow isn’t a one-and-done effort. It requires continuous improvement. Manufacturing units need to refine their equipment and workflows and implement improvements continuously.
Final Thoughts
One product at one time and one go: that’s continuous flow! It’s a lean manufacturing technique that’s the complete opposite of batch production and involves a whole workforce dedicatedly working on a single product until it’s completed before moving to the next one.
The results are incredible! Product quality becomes top-notch, chances of waste are at a bare minimum, and early detection in case of errors becomes easy.
