Properly implemented, Mixed Model Manufacturing can lead to 30% gains in productivity, shorter lead times, increased flexibility, and higher operator engagement.

1. Properly implemented, Mixed Model
Manufacturing can lead to 30% gains
in productivity, shorter lead times,
increased flexibility, and higher
operator engagement.
Download the Report: Advanced Mixed Model Manufacturing
Mixed Model Manufacturing Basics
Before moving on to the Advanced topics, I want to explain in more detail the
productivity gains that are possible through Mixed Model Manufacturing, since they
can be huge. Too big to be believed, in fact, unless we explain clearly how this can
happen. So, let’s break it down and look at how a 30% productivity gain could be
possible.

2. Productivity Strategy #1: Standardization as a requirement
The term we use for process documentation is “Standard Work Definitions”.
Documenting the “One Best Way” to do work, at the product and process level, is a
foundational requirement for Mixed Model Manufacturing, or for any Lean strategy for
that matter. The goal here is to document the detailed work steps, work times, quality
checks, material requirements, tooling and fixtures, and so on, for every product and
every process. This is a big job if you don’t do this already!
How does this impact productivity? In the process of standardizing you can identify
work steps as Value-Adding or Non-Value-Adding and eliminate the Non-Value-
Adding steps. You can do this right away or conduct process improvement work if it’s
needed. When you take out Non-Value-Adding work, productivity goes up.
Productivity Strategy #2: Designing optimum work flow
If you record a work flow, you’ll probably notice that a certain percentage of the time
the workers are not able to work. Typically, it’s for one of two reasons: they have
nothing to work on, or they have finished their work, but they can’t move the product
out of their station. Balancing work flow better is how you reduce this waiting time, so

3. that workers can add value more consistently, and be more productive. A part of the
balancing effort also includes the skillful use of buffers, or In-Process
Kanbans (download the Special Report to learn more about IPKs), as a balancing
tools.
Productivity Strategy #3: Formal Check-Do-Check practice
Obviously having to redo work will detract from productivity. One of the goals of your
Standard Work Definition is to analyze and remove quality risks. This is called Poke-
Yoke in Lean-speak. But what about workmanship errors that you cannot error-proof?
Another technique, which won’t eliminate errors completely but will help to catch them
sooner, is called Check-Do-Check. Check the work coming to you for quality issues, do
your work, then check your own work. Just this simple practice can cause a boost in
productivity by
1. Sensitizing operators to when errors can occur
2. Catching errors quickly, rather than letting them proceed down the line.
Productivity Strategy #4: Optimum sequencing plan
For Mixed Model Manufacturing, optimal sequencing is a must. Since different models
have different work content time, this variation will lead to increased starving and
blocking of the work flow, which leads to lower productivity. The optimum sequencing
strategy is developed during the line design process, based on product knowledge and
often with computer simulation tools.
Productivity Strategy #5: Optimum material flow system and
presentation
Productivity is going to drop like a rock, even with the best-designed line in the world,
if the materials needed are not delivered on-time, with the right part to the right location.
Operators will be waiting for needed material. Today companies are exploring the idea
of strategic kitting to give a further boost to operator productivity by reducing the time
and quality risk associated with part selection.

4. Productivity Strategy #6: Flexing as a way of life
I saved the best for last. The practice of flexing, or moving to the work, can be a huge
productivity boost. Remember that even if you do everything right and apply strategies
1-5, a Mixed Model line still must deal with work content time and process variation.
This will always exist, and it can’t be overcome completely. But if operators are willing
and able to move to where the work needs to be done, they can continue to add value
more consistently, and productivity will take a major jump up. This flexing is not “free
form”, but instead is based on a set of clear rules for when to move (and where) and
when to stay and work. Operators need to be trained in flexing. It won’t happen
organically.
Paying close attention to productivity, and to a deep understanding of the factors that
will hinder it, is an important part of the Mixed Model Line Design method. Variability
is the challenge, and by applying these 6 strategies, you will do a lot to overcome it.
However,
There are a hand-full of Advanced practices that make the difference in the performance
of your Value Stream or production line:

5. 1. Your ability to model and improve the work flow, before you physically
implement it. Apply the Six Balancing Tools to improve your design.
2. Your ability to define and manage the optimal sequence of production, or the
optimum lineup based on your backlog of orders.
3. The strategic use of buffers or In-Process-Kanbans to overcome process time
variability, and to smooth the work flow.
4. The willingness and ability of the production workers to move to the
work, instead of being stuck at a specific workstation.
In this special report we will be examining each of these four factors.
Download the Report: Advanced Mixed Model
Manufacturing
Best Regards,
Richard Rahn
Founder and Principal of Manufacturing
Leonardo Group Americas LLC
rrahn@leonardogroupamericas.com
1-303-494-4404
www.leonardogroupamericas.com
www.linkedin.com/in/richarddrahn
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