Kaizen: Step Three of the Deming Cycle: Evaluate Each Operation

If you have not already, you should read the Introduction to Kaizen and the previous article about measuring each operation.

Evaluate Each Operation

It is likely that, even during the “measuring” step, you have been evaluating performance. However, this is the formal step to list the evaluations.

It will once again be tempting to attempt overall evaluations. It can be terrific if you can devise a radical change…but it is more likely that you will succeed with many small steps. That is the kaizen approach, and it has been proven to work well.

It will also be tempting to become fixated on the first improvements that come to mind. However, you should approach this as police detectives should in criminal investigations: note everything but keep an open mind. One excellent approach is to carry two notebooks: one for the task at hand, which is to evaluate; the other for possible improvements. Simply note one sentence for any improvement that suggests itself, then turn your attention back to the evaluation step.

To evaluate the measurements taken in step two, compare them to the documented expected throughput logged in step one. What had been documented?

Raw materials
Machines
Processes: both manual activities and machine-driven
Outputs

Evaluating Raw Materials

The evaluation of raw materials will focus on quality concerns.

Are raw materials inspected, or sampled as they arrive from the suppliers?
Are there problems with the raw materials as they arrive from the suppliers? (Not on time? Defective? Damaged? Not conforming to specifications? Are these consistent problems, periodic or do they occur very rarely?)
Are raw materials inspected, or sampled as they arrive on the factory floor?
Are there problems with the raw materials as they arrive on the factory floor? Were these problems already present on arrival from the supplier? Were they caused in the storage environment or during transit from the warehouse?
Is there anything about the raw material, its packaging or presentation when delivered to the factory that is less than optimal? What could be improved?

Evaluating the Machines

The focus here is on throughput.

How does each machine’s measured throughput compare with the documented expected throughput?
Examine each step within one machine’s cycle, looking for delays or problems.
Is throughput reduced because of defects and rework?
Is throughput reduced because of breakdowns or maintenance cycles?
Is throughput reduced because some inputs are not available…such as lubricants or fasteners?

Evaluating the Manual and Machine Processes

The focus here is on unnecessary and inefficient processes. This is the most likely area for improvement.

What are the delays in procuring raw materials from suppliers? In moving raw materials from warehouse to factory?
Do people have to wait for equipment or people, like forklifts and their operators, before moving the next bin of raw materials into position?
Does the machine operator have a long process to unwrap or prepare material before beginning a batch?
Does the machine require set-up or maintenance before beginning a batch? Are the tools and materials stored as conveniently as required?
Are the processes well understood? Are printed and illustrated instructions posted where they can remind the operators?
How many times does the operator handle one item at one machine?
Is the operator forced to take measurements or make adjustments while working, or do parts fit into jigs so they must be correctly positioned and oriented?
Must the operator make awkward motions to move items? Conversely, is the operator forced to stay almost motionless for long periods of time?
Is the process so fast the operator is rushed? So slow that boredom sets in?
Are inputs and outputs loaded and unloaded automatically? How much work does the operator do to load an item and start the process on this machine? How much work to unload an item and send it to the next machine?
Are there steps that require more than one operator, such as a heavy lift?
Does the machine or the operator have to wait for inputs to arrive? For outputs to be cleared by the next stage?
Are there delays for quality checks on the output items?
Are there delays for recalibration or maintenance during a batch?
Are more consumables used than expected, such as lubricants or fasteners?

Generally you are looking for the time required to take an action, so the questions are:

Is this action necessary or beneficial?
Does it slow down production?

Evaluating the Outputs

This section is mainly about quality, rework and scrap. The Six Sigma approach provides a very rigorous methodology. The following guidelines should get you started:

At each machine or processing step, what percentage of the inputs become defect-free outputs?
What percentage need rework?
What percentage are scrapped?
Of the “defect-free” outputs, how many cause problems downstream because they are slightly off their ideal values?
Do they reach the customer on time, or are there further delays as the product leaves the factory?

After Evaluating: Prioritize, then Improve

The evaluation may now proceed in several different ways.

If the kaizen process is distributed among all the machine operators or across all the work cells, then each team can start working on planning their own improvements. Each team might prioritize either by trying to change whatever would have the greatest benefit, or by pursuing the easiest tasks to implement (the “low-hanging fruit”).

If the kaizen process is completely controlled by a small group, then they might prioritize the evaluations by identifying the steps that are farthest from ideal. Since kaizen is intended to take suggestions from all employees, it would still be wise to bring at least one concern to each front-line team. If the kaizen steering group must defer working with some teams, at least the “neglected” people will have something to think about in the meantime.

Please continue to the next article describing kaizen’s Deming cycle, which gives guidelines for the “Improve” step.

Oskar Olofsson, 2011

Kaizen

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I am a Swedish-based Lean consultant, and the owner of the World-Class-Manufacturing.com web site.

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