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Microlevel versus Macro Level - Ohba
Ohba says that one should start at the micro level — machines, cells, workstations, tooling, fixtures, operator job design, etc. — not at the macro level — lines, departments, suppliers, customers, etc. His reasoning is that you need to develop skills before you can address macro level issues. And he is saying that you should not start with VSM because it is a macro level tool. What Ohba does not say in his presentation is how you find out where in the plant you should start at the micro level. To me, an appropriate pilot project must meet the following conditions:
It must provide an opportunity for tangible, short-term performance improvements.
Both management and the work force in charge of the target process must be willing and able.
The target process must have at least one more year of economic life.
To identify such opportunities, you need to observe operations directly, interact with operators, managers and engineers, and analyze data. VSM is one of the tools that are useful in doing this, but it is not the only one, and it is not always needed.
One week of process kaizen and one week of system kaizen. During that week we used MIFD. Later on they started using it more and more in the plants only when needed.”
The “Value Stream Mapping” Label
“Materials and Information Flow” accurately describes what the technique is about, and is almost self-explanatory.
According to Gary Stewart, a 23-years Toyota veteran:
“The VSM process was known internally simply as “process mapping” – (or occasionally later as MIFD – but that was more specific to OMCD ) – it is only one of a suite of tools that should be used together to understand the process from high level to great detail. I think today the term VSM and the use by consultants of the term VSM is more of creating a branding difference in both Marketing and Consulting. In Marketing “process mapping” does not sound very sexy – But with Value Stream Mapping – you have a major brand differentiator.
Unquestionably, Jim Womack is an outstanding marketer. “Process Mapping,” “Materials and Information Flow Analysis,” are all terms that, at best, appeal to engineers. Any phrase with “value” in it, on the other hand, resonates with executives and MBAs.
Ohba says that one should start at the micro level — machines, cells, workstations, tooling, fixtures, operator job design, etc. — not at the macro level — lines, departments, suppliers, customers, etc. His reasoning is that you need to develop skills before you can address macro level issues. And he is saying that you should not start with VSM because it is a macro level tool. What Ohba does not say in his presentation is how you find out where in the plant you should start at the micro level. To me, an appropriate pilot project must meet the following conditions:
It must provide an opportunity for tangible, short-term performance improvements.
Both management and the work force in charge of the target process must be willing and able.
The target process must have at least one more year of economic life.
To identify such opportunities, you need to observe operations directly, interact with operators, managers and engineers, and analyze data. VSM is one of the tools that are useful in doing this, but it is not the only one, and it is not always needed.
One week of process kaizen and one week of system kaizen. During that week we used MIFD. Later on they started using it more and more in the plants only when needed.”
The “Value Stream Mapping” Label
“Materials and Information Flow” accurately describes what the technique is about, and is almost self-explanatory.
According to Gary Stewart, a 23-years Toyota veteran:
“The VSM process was known internally simply as “process mapping” – (or occasionally later as MIFD – but that was more specific to OMCD ) – it is only one of a suite of tools that should be used together to understand the process from high level to great detail. I think today the term VSM and the use by consultants of the term VSM is more of creating a branding difference in both Marketing and Consulting. In Marketing “process mapping” does not sound very sexy – But with Value Stream Mapping – you have a major brand differentiator.
Unquestionably, Jim Womack is an outstanding marketer. “Process Mapping,” “Materials and Information Flow Analysis,” are all terms that, at best, appeal to engineers. Any phrase with “value” in it, on the other hand, resonates with executives and MBAs.
Operations Science View of Value Stream Mapping
Art Smalley’s perspective on VSM
“Value stream mapping, for instance, is perhaps the most widely used tool in lean programs today.
A third dimension, human motion, is often added to the mix for consideration as well at Toyota. As TPS evolved internally and was rolled out to supplier companies externally a consistent problem was insufficient investigation into the details of material flow, information flow, and human motion in the process. It became a requirement for engineers and others in charge of manufacturing processes and line conversion work at suppliers to make maps.
The emphasis was to draw both detailed standardized work charts depicting operator motion, and flow charts depicting material storage locations, scheduling points, and operator work sequence before the start of production. In other cases, this tool was used externally to find ways to convert lines to more efficient ones.
The key point is that the tool was created to analyze and solve a specific category of problems Toyota faced in new production lines and in helping suppliers implement lean. From this fairly specific local origin in Toyota, the tool was slightly modified (the human motion emphasis was reduced) and popularized in the U.S. by my good friend and former Toyota colleague John Shook, and his co-author Mike Rother, in their insightful, best selling workbook “Learning to See”.
The book is about learning to see what is primarily a material and information flow problem, or essentially elements of the JIT pillar of Toyota’s production system (flow, takt time, level, and pull production).
By design it doesn’t even attempt to address the topic of Jidoka for example which Toyota considers an equally if not more important support pillar than JIT or equipment stability. The technique used in the workbook simply measures the overall manufacturing lead-time versus production value add time. Everything non-value adding (i.e. the waste) is to be eliminated and answering seven specific questions outlined in the workbook will help you accomplish some of this goal.
Overall, however, when the 4M’s of manufacturing (man, machine, material, and method) are considered you’ll realize that this tool mainly considers the material (and information) flow component. The other 3M’s are much less emphasized and one other important M – metrics – is expressed chiefly in terms of lead-time and value-add time.
This is fine for Toyota. Internally they well know the limits of the tool and understood that the it was never intended as the best way to see and analyze every waste or every problem related to quality, downtime, personnel development, cross training related issues, capacity bottlenecks, or anything to do with profits, safety, metrics or morale, etc.
No one tool can do all of that. For surfacing these issues other tools are much more widely and effectively used. Unfortunately, the average user of the workbook tends to copy the pattern expressed in value stream mapping regardless of the nature of their manufacturing problems.
The unintended consequence of the success of the method has been to convince many people that it is a universal tool for identifying all problems in manufacturing operations.
This guidance however biases companies with major quality, downtime, or factor productivity problems to deemphasize them since those items are not surfaced well using the method and questions outlined in value stream mapping. The tool just does not frame these problems well by design. Couple this effect with the fact that most lean efforts already have a disproportionate bias towards the concept of “flow”, and there is a recipe for inherent danger.
For example instead of learning to see what is truly broken in their processes companies wind up typically focusing on a particular subset of operational problems chiefly that of flow and lead-time related issues.”
John Shook in VSM Misunderstandings - http://www.lean.org/library/shook_on_vsm_misunderstandings.pdf
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