Implementing Lean in a Job Shop

Lean Implementation in a Job Shop

First and foremost, it’s important to emphasize the 5 Lean Principles must be followed in any type of lean implementation:

1. Specify Value (In the Eyes of the Customer)

2. Map the Flow of Value (Create Value Stream Maps)

3. Achieve Continuous Flow (Flow Where You Can)

4. Install Pull (Pull Where You Can’t Flow)

5. Seek Perfection (Continuously Improve)

It’s the application of these 5 principles, particularly Principles #3 and #4, that changes based on the type of business you have.

Job Shop Low-Volume Businesses are characterized by custom orders of very low quantities of product, often by a customer who doesn’t want to wait a long time for delivery.

How does Lean apply here?  You might be thinking that it doesn’t, that you’ll have to respond to actual customer orders using a “push” scheduling system, and do the best you can with lead time.

Well…..you can use Lean Principles in a Job Shop business just as effectively as in high-volume repetitive businesses.  The difference is in your flexibility.  In a Job Shop environment you’ll need 10X more flexibility!

We find in many of these job shop enterprises, after developing product family matrices, that a number of products are repetitive anyway.   If they’re repetitive, you can set up dedicated cells, pull systems, and short lead times to respond to these customers.  This will probably cover about 80% of your volume, but only about 20% of your customers.

The other 80% of your customers (and 20% of your volume) probably is true “job shop” demand. For these customers you’ll need to set up and run a highly flexibly value stream that can easily changeover (<100 seconds) based on rapidly changing low volume demand.  I’ve working in places where we’ve simply called these assets our “all other” Product Family Value Stream.  This is the one you’ll need small-scale flexible equipment, a lower level of automation, a high degree of cross-training, and flexible people who’ll instantly move from cell to cell and line to line when required.  One other difference between Job Shop and Repetitive is the cells may not be staffed anywhere near 100% of the time.  “Staffing to the Interval” is the issue in Job Shop businesses.

The one lean tool that may not apply as well is the Finished Goods Supermarket Pull system.  This is because you would not typically be carrying finished goods for a job shop in a supermarket, sell them out of there, and then pull production to replenish the supermarket….every item is purely “make to order”.

These lean tools all apply to a Job Shop environment:  5S, Visual Controls, SMED, TPM, FIFO Lanes, Mistake Proofing & Fail Safe, POUS, Heijunka, Kanbans, Physical Layout, Flow Cells, and Standard Work.  Because of the need for high labor flexibility here, we’d also see high utilization of TWI Job Instruction to develop the multi-skilled workforce a Job Shop requires.

And we still need to apply the five Lean Principles: 1. Value, 2. Map Value, 3. Flow, 4. Pull, and 5. Seek Perfection to these Job Shop value streams.