Single Piece Flow

Will Six Sigma Be Relevant For The Future
  • Single Piece Flow states the concept of moving one work-piece / Service at a time between operations/processes within a work cell.
  • At the opposite extreme, we might process an entire batch or lot at each operation before moving it to the next process. This idea has many benefits.
  • Single piece flow works best in combination with a cellular layout.

Batch Production Vs Single Piece Flow

Will Six Sigma Be Relevant For The Future
  • Consider a scenario where 10 parts must be produced through 3 processes A, B & C
  • In the batch production, all the first 10 pieces are completed for process A, followed by Process B followed by Process C, whereas in Single piece flow, all parts flow through the process one by one

Single Piece Flow Advantages

Will Six Sigma Be Relevant For The Future
  • Balanced cycle time among all the processes and reduced change over time is key to reducing production lot sizes and improving flow by reducing production loss and output variability.
  • The word "one " does not necessarily have a literal meaning.
  • It keeps WIP at the lowest possible level and encourages work balance
  • It is easy to identify the Kaizen through this method
  • It improves quality, reduces manufacturing defects and wastes

Expert's Comment

  • Single Piece Flow by far the most difficult concept to embrace. How do you overcome it?
    1. Don't look at single-piece flow, especially when you have colossal batch sizes
    2. Go with an incremental approach; say, if the current batch size is 100, look at how it can be reduced to 70.
    3. Have an action plan to reduce from 100 to 70, and build consensus
    4. Once you achieve 70, stay there for a while till the process reach the equilibrium stage
    5. Repeat the above 2,3,4 steps multiple times as long as each reduction is resulting in Return on Investment When you do the ROI calculation, ensure you consider opportunity losses as well & potential increase in sales as well.