Origin of JobshopLean

A Fundamental Limitation of Lean

For every OEM like Toyota, there are thousands of small-to-medium manufacturers (SMM) whose operations simply do not match those of an assembly line.  Most SMMs tend to be HMLV (high-mix low-volume) custom manufacturers, or worse, they operate like job shops.  The Toyota Production System (TPS) is not the complete solution for these HMLV (high-mix low-volume) manufacturers because many of the revolutionary operational strategies of the TPS are primarily suited for assembly line production.  The majority of the popular Lean tools were never designed to handle the operating conditions and constraints of high-mix low-volume (HMLV) manufacturing facilities, as shown in Table 1.       

 

Table 1 TPS/Lean Tools to Use or Avoid for HMLV Manufacturing

 

TPS/Lean Tools to Use for HMLV Manufacturing	TPS/Lean Tools to Avoid for HMLV Manufacturing
Strategic Planning	Value Stream Mapping
Top-Down Leadership	Assembly Line Balancing
Employee Engagement	One-Piece Flow Cells
5S	Product-specific Kanbans
TPM (Total Productive Maintenance)	FIFO Sequencing at Workcenters
Setup Reduction (SMED)	Pacemaker Scheduling
Error-Proofing (Poka-Yoke)	Inventory Supermarkets
Quality At Source	Work Order Release based on Pitch
Visual Controls/Visual Management	Production based on Level Loading (Heijunka)
Product and Process Standardardization	Mixed Model Production with Takt Time
Jidoka	Right-sized Machines
Standard Work

It is essential that HMLV manufacturers embrace the philosophy and principles of Lean.  But, they must also carefully select a manufacturing strategy that suits them.  In turn, their choice of manufacturing strategy will force them to significantly change the methods and tools they use to implement that strategy.  Today, there is a clear-cut need for a viable production system model that could be implemented by the thousands of small-to-medium (SMM) high-mix low-volume (HMLV) manufacturers in the US alone!

 

Advancing Lean to High-Mix Low-Volume (HMLV) Manufacturing

JobshopLean is essentially a modification of the five-step process for implementing Lean proposed by James Womack and Daniel Jones in their bestseller book published in 2003, Lean Thinking.  Unfortunately, while the Womack-Jones process for implementing Lean may be universally applicable in bits and pieces, many of the Lean tools that are used to implement that process are unsuitable for HMLV environments.  In the case of any HMLV manufacturer, such as a CNC machine shop, fabricator or custom forge shop, the TPS/Lean tools are incapable of implementing the three major steps in the Womack-Jones process for implementing Lean:

1. Map the value stream: Identify all the steps in the value stream for each product family, eliminating whenever possible those steps that do not create value.
2. Create flow: Make the value-creating steps occur in tight sequence so the product will flow smoothly toward the customer.
3. Establish pull: As flow is introduced, let customers pull value from the next upstream activity.    

 

How JobshopLean Differs from Lean

JobshopLean is similar to, but also differs from, Lean as follows:

1. It completely embraces the human resource aspects of the Toyota Production System such as management involvement and engagement with employees, cross-training of employees, kaizen events executed by employee teams, etc.
2. Its toolkit includes the TPS/Lean tools listed in the left-hand column of Table 1.
3. Its toolkit replaces the TPS/Lean tools listed in the right-hand column of Table 1 with tools that are appropriate for design and operation of an HMLV production system in the 21st Century.
4. It requires that the ERP system being used by an HMLV manufacturer have the capabilities/functions to plan, schedule and control shop floor (and office) operations that do not have the cadence that exists in assembly line manufacturing.    
5. It emphasizes major revision of university curricula so that the education and training of future Industrial Engineers and Operations Managers gives them real-world knowledge and industry experience in implementing Lean, Six Sigma, Theory Of Constraints, etc. before they enter the workforce.

 

Additional Reading

Please click here to listen to a seminar JobshopLean vs. ToyotaLean: Why the Toyota Production System is Unsuitable for Jobshops.  

Please click here to access the article The Robust and Reliable Job Shop: Going Lean Requires More than the Traditional Lean Tools.

Please click here to access the article Adapting Lean for high-mix low-volume manufacturing facilities. Gear Technology, (2012, August), 10-12.

Please click here to access the report Recession-Proof your Shop the Lean Way.