One Piece Flow and Making it Work for You
Every lean manufacturing goal is to achieve one piece flow. One piece flow allows for the most efficient production operations. It has taken Powerblanket many years to achieve one piece flow production. To maintain this production process requires overcoming challenges such as maintaining standards, level loaded schedules, continuous training, and waste reduction.
One Piece Flow
One piece flow is centered around balanced cycle times, takt time requirements, and a level loaded schedule. Takt time is the rate at which a finished product needs to be completed to meet customer demands. We have built our production lines to meet desired takt time calculations and expand production cells to lower takt times if needed. Takt times are met by achieving balanced cycle times from cell to cell. Cycle times are individual times per production cell that records process time and delay time. Powerblanket has also designed an internal scheduling software system to meet our unique application and processes. Our schedule is driven from takt times and available operators to output total units to be built and time requirements to follow.
Traditionally, like many manufacturing environments, Powerblanket had been producing product using the “batching” process. This process is obsolete here at Powerblanket as we have transitioned to the more beneficial “one piece flow” process. One piece flow
Benefits of One Piece Flow
- Inventory Reduction: Companies can maintain a small volume of safety stock reserved for standard products. The majority of volume is built from customer demands. This requires each operation to only build product needed by the next operation.
- Floor Space Reduction: Each operation is built one piece at a time so removal of WIP (work in progress) areas allows for a more condensed layout. This opens up space for additional production lines. As a result for floor space reduction, there is a minimized needed for operators to oversee production areas.
- Flexibility: Our production lines are very unique because we have the flexibility to alter models being produced daily. Our lead times are then decreased as well for we have very minimal changeover times and downtime when switching models.
- Lead Times: Our production lines have lead times given to each model from understood takt times. This makes a very predictable value stream.
- Quality Control: We encounter much less wasted product and quality issues with the one piece flow process. Any quality issues or defective material are found on the first unit, and are then revised/resolved for the next unit. Since batch sizes in one piece flow are just one, there will not be mountains of inventory to count, move, store, and dispose of.
- Calculate takt time for products and ensure all cycle times are either less than or equal to total desired takt time.
- Evaluate production cells and base process/equipment capability on takt time. Considerations include changeover times, load and unload times, downtime, and machine speeds.
- Develop a pull system that allows for reduced lead times, ultimately benefiting customers. Allow for the value stream to drive the pull system.
- Develop a lean layout that allows for highest efficiency possible within the smallest amount of space. Space between process and within process cells must be minimal to eliminate motion waste and prevent unwanted WIP (work in progress) waste. Layout shapes and directions are driven from process requirements and factory floor limitations.
- Create visible standard work processes with the use of standard operating procedures, jigs/fixtures, quality checks, and 5S workstations. Standard processes eliminate variability and inconsistencies to drive quality. Consider accommodations for the differences between standard and custom products.
- Determine number of operators required to meet takt times. Train operators from standard work and cross train to allow for maximum flexibility.
- Allow a learning curve to develop and audit takt times and standard work over time to achieve maximum quality and efficiency.