Day: July 11, 2014

Batch-and-Queue vs. One-Piece Flow: Quarter Activity

At Wednesday’s (7/9) Lean Implementation Leaders and Lean Facilitators meeting, Bob Hiltunen (Director, Auxiliary Services) provided a wonderful teach back activity on the advantages of one-piece flow processing vs. batch-and-queue processing.

Background

One-Piece flow is one of the most important principles of lean manufacturing. One-piece flow means that parts are moved through operations from step-to-step with no work in process in between; either one piece at a time or a small batch at a time. Once work on a product begins it never stops moving until it is a finished product.

As opposed to one-piece flow, batch-and-queue processing is the action of producing more than one piece of an item and then moving those items forward to the next operation before they are all actually needed there. Batching and queuing tends to drive up inventory and lead time, and creates inefficiency in an operation. It also increases the space needed for production.

Teach back Activity

LIL’s and Facilitators Participating in the Teach back Activity

To complete this activity, 2 “directors,” 4 “managers,” 4 “workers, and 1 “customer” are needed. Each worker is a “station” at the table (as seen in the photo). The first three workers are assigned the task of flipping quarters and passing them to the next worker and this process repeats until the quarters reach the last worker who is asked to “stamp” them, and pass them to the customer.

The activity begins by simulating a batch-and-queue system with the first worker flipping all 30 quarters before passing them, in a batch, to the next worker and so on until they reach the customer. The batch sizes that are passed between workers are reduced after each subsequent round until each worker is flipping and passing only one coin at a time, to represent a one-piece flow system.

To measure the effect of the transition to one-piece flow, time measurements are taken at many times during the process:

  • At the start of the process when the first coin is flipped
  • When each worker first receives a coin from the previous worker
  • When each worker flips and passes their last coin
  • When the customer receives the first coin
  • When the customer receives the last coin

As the activity progresses, the time each work station is active gradually increases, however, the time it takes for the coins to reach the customer dramatically decreases. In our simulation, the process time was reduced from 1 minute 30 seconds to 20 seconds.

The ideal state for a production process is continuous one-piece flow. If you can’t manage to get down to one-piece flow, always the question … can you get two-piece or three-piece? The most important thing to remember is the idea of continually moving closer to the ideal state.


Create Constancy of Purpose

W. Edwards Deming
W. Edwards Deming

William Edwards Deming, a statistician and professor, developed a theory of management based on fourteen points that he considered critical for management to become transformational and thus lead their business to greater success. He published his ideas in a book titled “Out of the Crisis” and I recommend you get a copy for reference. His thoughts and published works have led to the development of systems like Total Quality Management, Six Sigma, and Lean. Deming’s work is not a blueprint for success, ready to be copied, but his fourteen points are a starting point for discussion, consideration and contemplation when it comes time for you to begin your journey of management transformation and improvement.

Let’s start this journey together, now, as we discuss Deming’s points and see how they may relate to you and your leadership style and business goals.

Point One: Create constancy of purpose toward improvement of product and service, with the aim to become competitive and to stay in business, and to provide jobs.

Seems pretty simple right? Well, this one little sentence is packed with complexity just waiting for us to unravel. This point squarely puts the onus on Management to make looking out for our employees the number one job, while the responsibility of the employee is to improve their product or service. The focus is not on the product or service; rather, the focus is on choosing to dependably improve our product or service. Acknowledge that what you offer isn’t perfect and can be done better. And if it isn’t done better by you, reliably, your competition will do it for you and put you out of business.

Deming also advocates that you focus your business on being competitive and providing jobs. To truly improve our competitiveness, I feel we must recognize the value our staff bring to our business, and concentrate on allowing them to self-improve. People—not the thing we produce or the service we provide—are at the core of our operation. Without our employees, nothing is made, nothing is sold, and no amount of marketing nor motivational speeches will change that – our staff make our business. Empower them.

The secret to success...
Benjamin Disraeli said it succinctly

Benjamin Disraeli said it most succinctly – and I believe Deming would agree – that to truly succeed in your business Management must fully embrace continuous improvement as a living element in our operations, making it the basis of the corporate culture. Staff should be 100% supported by the the company and the management. Staff should be empowered to make positive changes to improve their working environment and better their product or service.  And there should never be any doubt that the company fully supports continuous improvement efforts.

As we continue this journey through Deming’s fourteen points, we’ll see how each point can easily stand on its own, while at the same time often reinforcing one another—much like management and staff have their own jobs to do but must work together to keep driving improvement forward to increase productivity.

Next Article: Point Two – Adopt the new philosophy