In a world that is ever-changing and fast-paced, manufacturing and production facilities must be able to change with the times. This means reducing waste and cycle times while also increasing productivity. How can this be done?
Through one-piece flow.
One-piece flow is “a way of running a process in which units are moved one at a time through all process steps”. In other words, it is a linear process in which each unit is completed before the next unit is started.
One-piece flow vs batch
One-piece flow contrasts with batch processing because items are processed one at a time rather than in batches in which units are processed in groups. The main goal of one-piece flow is to reduce or eliminate waste (including overproduction, motion, inventory, waiting, defects, and non-utilized talent) and increase value-added activities.
How to achieve a one-piece flow
To achieve one piece flow, there must be a smooth and even flow of materials through the process. This requires balancing the demand with the supply so that there are neither too many nor too few materials moving through the process at any given time.
One-piece flow allows for smaller inventories, which leads to less waste because less material can become damaged or obsolete before it is used. In addition, one-piece flow enables quick detection of defects so that they can be fixed immediately before they cause further problems downstream.
Why is one-piece flow better?
Reduced Work in Progress Inventory
One of the most significant advantages of one-piece flow is that it helps to reduce work-in-progress (WIP) inventory. WIP inventory refers to unfinished products that are sitting in the production process. When WIP inventory builds up, it can lead to bottlenecks and delays further down the line. By contrast, one-piece flow minimizes WIP inventory because finished units are immediately moved to the following process. This helps to keep the production line moving smoothly and reduces the likelihood of delays. By reducing the work in progress, we move towards a more agile mindset.
Improved Quality Control
Another benefit of one-piece flow is improved quality control. When units are processed in batches, it can be difficult to identify defects until the entire batch has been completed. This can lead to wasted time and resources if the entire batch needs to be scrapped. With one piece flow, however, defects can be identified immediately and corrected before further processing takes place. This helps to improve the overall quality of the finished product.
Increased Productivity
One-piece flow also leads to increased productivity because there are no bottlenecked processes or waiting periods for other parts of the batch to be completed. When all processes run smoothly and efficiently, it helps to keep the entire operation running like a well-oiled machine. In addition, workers tend to be more engaged when working on one unit simultaneously instead of struggling to keep track of multiple units concurrently.
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What are the benefits of One Piece Flow?
The main advantage of one-piece flow over batch processing is that it reduces or eliminates many types of waste:
Overproduction:
When units are produced in batches, there is always the potential for overproduction because you cannot predict how many units will be demanded by customers. This results in stockpiling inventory, which takes up space and incurs additional costs for storage. With one piece flow, only the amount of units demanded by customers are produced, which eliminates the possibility of overproduction and the waste associated with it.
Motion:
Batch processing often requires workers to walk back and forth between different workstations to retrieve materials or tools needed for their tasks. This results in wasted time and effort and an increased likelihood of errors due to fatigue. In contrast, one-piece flow enables workers to have everything they need at their workstations to work on the unit from start to finish without leaving their station.
Inventory:
As mentioned above, batch processing often leads to stockpiling of inventory (finished goods and raw materials). This not only takes up valuable space but also incurs additional costs for storage. In addition, stockpiling increases the risk of damage or obsolescence because the longer an item sits in storage, the greater the chance it will become damaged or no longer meet customer demands. One-piece flow minimizes inventory levels by producing only what is demanded by customers and replenishing inventory only when necessary.
Waiting:
When units are processed in batches, there tends to be downtime between steps while workers wait for all units in a batch to be completed before moving on to the next step. With one-piece flow, however, since each unit moves through the process independently from other units, there is no downtime between steps since workers can start working on each unit as soon as it arrives at their station.
Defects:
Batch processing makes it more difficult to detect defects because by the time a defect is identified (usually during quality control), numerous units may have already been produced with the same defect. Therefore, fixing the problem becomes much more costly since all defective units must be scrapped or reworked. In contrast, since each unit is processed independently in one piece flow, any defects can be immediately identified and fixed without affecting other units in the process.
Non-utilized talent:
When workers are specialized in only one task and work on batches of units (as opposed to working on individual units), they often feel like they are not contributing fully to the manufacturing process and their talents are not being utilized to their fullest potential.
In contrast, working on individual units enables workers to see their contribution more clearly and feel like they are adding more value since they complete each unit from start to finish.
"One-piece flow is one of the basic concepts of lean manufacturing and it refers to the manufacture of products one at a time, in a continuous flow."
What are the one-piece flow disadvantages
Requires more space: One-piece flow typically requires more floor space than batch processing because each unit must move through the process independently from other units. In contrast, batch processing can be done in smaller areas since units can be processed together in groups.
More expensive to set up: Setting up a one-piece flow can be more expensive than batch processing because it often requires the purchase of additional equipment and materials (e.g., workstations, tools, etc.)
More training required: Since one-piece flow typically involves workers performing multiple tasks instead of specializing in one task, more training is often required to ensure that workers are able to perform all tasks correctly.
Not always possible: In some cases, it may not be possible to implement one-piece flow due to the nature of the product or process. For example, if a product requires a long drying time between steps, one-piece flow would not be possible since each unit would have to wait for the previous unit to dry completely before moving on to the next step.
One-piece flow is a manufacturing process in which units are processed one at a time and move through the process independently from other units. This type of flow minimizes inventory levels, waiting times, and defects while maximizing utilization of talent and space. However, one-piece flow can be more expensive to set
Conclusion:
Implementing a one-piece flow can help manufacturing and production facilities reduce waste while increasing productivity levels. By eliminating overproduction, motion, inventory levels, waiting periods between steps, defect rates, and non-utilized talent, one-piece flow helps create a leaner manufacturing process that saves time and money. If your facility is looking for ways to improve its efficiency, the one-piece flow might be the answer.
