How to Implement the Lot Size of One

April 21, 2008 

Hi MBBP Subscribers, 

Most practitioners cringe when the lean manufacturing guru talks about the lot size of "one." Many can't relate to it because of the complexity of their operations. How do we go from an MRP shop order, "launch and expedite," manufacturing methodology to sequential, "lot size of one," production? No one said it would be easy, but again, how do you eat an elephant? 

If you have a hard time visualizing how you get to the lot size of "one," be sure to read this weeks article, "Sequential Production: The Lot Size of One, Rules!"

Have a nice day, and stay connected.

  

Bill Gaw
Business Basics, LLC
6003 Dassia Way
Oceanside, CA 92056
bg@bbasicsllc.com 
760-945-5596

Sequential Production: The Lot Size of One, Rules!

Effective shop floor control has proven elusive as we have upgraded our manufacturing control system from MRP to MRPII and then to ERP. To capture control of shop floor activities, we need to stop beating a "dead horse" and start implementing and improving the sequential production process. The winners are! 

It takes more than systems sophistication for manufacturing companies to gain control of factory operations. To achieve on-time shipments at healthy profit margins, companies need to continuously improve obsolete MRPII/ERP shop order "launch and expedite" systems with the simplicity of sequential production.  

The assertion that sequential production only works in high production, widget-manufacturing environments is a myth. Leading low-volume, "make-to-order" manufacturers are improving schedule flexibility, customer responsiveness and profit margins by developing and implementing the Sequential Production Process.  

Henry Ford first introduced sequential production at his River Rouge operation in 1920. Using sequential production as a basis for his production line concept, the Ford plant was able to go from receipt of iron ore to casting the engine block, and to shipment of the machined engine block in a final assembled car in an astonishing forty-eight hours. Ford's success, however, was limited by a manufacturing philosophy that called for the absolute power of a management hierarchy.  

Today the success of sequential production is in the hands of production workers and team dynamics. Some of the responsibilities of the line worker in today's sequential production environments are production tools and instructions, logistic layouts, operations content and sequencing, and cycle time management.

The improvement of speed, quality, costs are all placed within the responsibility and control of the production worker through team dynamics. 

Sequential production is neither an inventory control system, nor a replacement for MRP. It is an organized and focused assault on production flexibility, speed, quality and costs. It is a process that requires total employee involvement and participation in the continuous improvement of manufacturing performance. It focuses on cycle time reduction via reduced lot sizes and setup times, preventative maintenance, workplace integrity, visual scheduling and worker flexibility. Sequential production tools and techniques include process capabilities, reduced process variances, causal analyses with root cause determination and relevant corrective actions. 

While starting a sequential production project at the end of the production process is good advice, one heavy equipment manufacturer started at the front because they could never start a customer's machine build on time as they always had to wait for the machine's welded base structure to be finished. The excuses for the delay: late shop order releases, raw materials shortages, no one told us to start, and it's a huge, complex, time consuming project.  

We decided to break the machine structure build process into a six-station sequential production work cell:  

    1) raw materials prep,

    2) sub-assembly welding,

    3) frame welding,

    4) tank build/installation,

    5) manifold build/installation and

    6) painting.  

The plan was to set the lot size to one and to flow the work from one station to the next using visual scheduling and point-of-use logistics.  

To everyone's surprise and delight, not only did this new production process make life easier for the weld shop personnel, it increased productivity and improved quality and eventually even reduced inventories. But most important, customer lead-times were reduced because machines no longer had to wait for the welded base structure. 

A good approach to sequential production process implementation is first to train all workers in the continuous improvement process (kaizen) and team dynamics. Next is to select a logical pilot project that would be carried out in advance of the rest of the plant "roll-out". The project should provide an area that can be isolated from material flows in the rest of the plant, but with production processes similar to the rest. The objective is to gain a quick success before "roll-out" to convince the skeptics that it is the way to go.  

If your company needs a little implementation help, check out our Lean Manufacturing Training Package at: 

                     http://bbasicsllc.com/kblm.MBBP.htm

The World class Manufacturing Training Modules 

Manufacturing leaders have a responsibility to educate and train their team members. To preview 7-cost-effective, e-learning modules that will help you get to where you need to go. simply click on the below link: 

http://bbasicsllc.com/training-modules.MBBP.htm

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