Lean Six Sigma Improvement Through Modular Kaizen

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Are your employees constantly fighting fires? Are the problems one-off events or predicable consequences of the way you do business? Grace L. Duffy and John W. Moran look at using Modular kaizen so that you can put out fires while still supporting strategic, system wide process improvement.


Modular kaizen [1] is an organizational improvement approach designed for busy workplaces with a high level of interruptions. The tools of Modular kaizen assist improvement teams to gather and analyze data about disruptions to expected operations and make informed choices about returning to a stable system. Modular kaizen has been successfully applied through both the traditional Plan-Do-Check-Act (PDCA) cycle [2] and the more recent Lean Six Sigma (LSS) family of improvement cycles.

Budgets have taken a significant hit during the recent economic downturn, causing a reduction in workforce and an increase in workload to meet customer needs. This two-edged sword of forced change has encouraged an interruptive, crisis approach to daily work. The increasing use of mobile communications has further exacerbated this short-term, "quickly-respond-to-crises" culture. Constantly responding to crises takes a toll on the employees involved. Frequent crises increase employee stress levels by constantly pulling staff away from daily work which must be accomplished to meet long-term customer needs.

The Modular kaizen model using the concepts of Lean and Six Sigma starts with the need for effective change management. The Define phase of the DMAIC (Define, Measure, Analyze, Improve, and Control) is used to investigate the situation to see if a disruption to the expected workflow has a special cause or whether it is a normal variation of a standard process. Once the disruption is identified, the Limited Information Collection Principle [3] guides data collection of performance measures to establish the severity and urgency of the disruption, identify who and what is impacted, and estimate the disruption timeline. In the LSS DMAIC cycle, this monitoring is performed during the "measure" phase of the improvement process.

The next step is "analysis."Based on the data gathered in "measure," the response team does one of the following:

  • Do nothing – continue to monitor the disruption until it has either dissipated or needs more attention. If more analysis is required, investigate by establishing a team to investigate the disruption (analyze) and report back. The information reported back to process owners is in the form of a high-level scope document.
  • Respond by taking short-term actions that apply all available resources to stabilize the process. The full DMAIC cycle is employed to solve the disruption and bring it under control.

Modular kaizen flow using the Lean Six Sigma DMAIC approach is shown in figure 1.

Figure 1: Modular kaizen improvement cycle flow [4]

A Modular kaizen approach minimizes disruptions by making sure no "analysis" is executed until "measure" has been done to establish the baseline measurement of where a disruption begins. When any action is taken, it is done in an informed manner. The analysis is short term, based upon a comparison of expected process performance with data gathered from the actual performance experienced. If the disruption is within the expected variation of the process as it is defined, the incidence is documented and the process either continued as defined, or improved within current criteria to prevent a recurrence of the disruption.

Once the disruption is fully defined, if it is found to be a special cause outside the normal criteria of the process, a team is chartered to develop a plan using the complete DMAIC cycle. The Define phase of the DMAIC cycle identifies changes to the process intended to prevent the disruption from occurring again. This second cycle of "measure," "analyze," and "improve" validates (measures) the final improved outcome and employs the control phase of the cycle to document the changes for future sustainability.

This small M, A, and I cycle is the basis of Modularkaizen within the Lean Six Sigma improvement cycle. The sustainability function of a stable operating process includes constant monitoring of performance to assure the process is still capable of meeting customer requirements within normal limits. If customer requirements have changed to the point where the existing process is no longer capable of meeting specifications, then a full improvement study and DMAIC improvement process is employed.

Analyzing a System Disruption:

The Modular kaizen approach minimizes disruption by making sure no "improvement" is executed until "measure" has been done and data has been "analyzed" to identify the reality of the current situation. Modular kaizen is an approach that resists the urge to panic in the face of a disruption. Once the process is stabilized, a full DMAIC cycle is undertaken to develop a plan and action steps to proactively minimize the recurrence of the disruption. The final step at the end of any Modular kaizen activity is to document successes and lessons learned.

When a disruption occurs in a stable system, the impact it has caused must be defined. One way to analyze the disruption is to identify what has been impacted in the overall system using a Disruption and Impact Matrix as shown in figure 2. The first step is to identify what areas were impacted in the current stable state. These impacted areas are called Areas of Concern (AoC). AoC can be functional as well as system-level concerns. Once the AoC are documented, a broad sense of how they are impacted is determined. The next step is to analyze whether the impacted areas are under the control or influence of the organization. If the organization controls the process under study, action can be taken directly to minimize the impact. If the organization can only influence the AoC, taking action might be slower since others need to be involved before making decisions to stabilize the current state.

Figure 2: Disruption and Impact Matrix

The AoC should be prioritized within both control and influence categories. It is best to start with the AoC that have been most strongly impacted. Prioritizing stabilization efforts is most valuable when faced with limited resources.

Once the AoC are prioritized, they can be analyzed using a Force and Effect Diagram + ca [5] or Disruption and Impact Diagram. Both tools are useful as a response team analyzes and makes small improvements to stabilize the situation. [6]

Example 1 - Disruption Caused by Budget Cut:

A disruption many organizations encounter is the reduction in budgets from one year to the next and the impact it has on services which can be provided. The following example shown in figure 3 is one in which a department has to cut its budget by 25%. Some Areas of Concern (AoC) generated by a senior management team might be:

  • Staff Loss
  • Program cuts and degradation
  • Loss of funds
  • Loss of public support
  • Media interpretation of the events
  • Reduced customer satisfaction

The team should prioritize the AoC by those most likely to occur needing an immediate response and those under department control. Understanding up front the most important items over which they have control helps begin the Modular kaizen process. The AoC over which they have influence also need to be prioritized. These areas must be monitored to ensure they are not impacting those areas under department control.


Figure 3 shows AoC diagramed to illustrate how the Disruption and Impact Matrix can be used to capture team analysis of a disruption.

Figure 3: Disruption and Impact Matrix

The Disruption and Impact Diagram shown in figure 4 aids in further analysis of the AoC. Two of the AoC are shown in figure 4. Things the team might measure and analyze under staff cuts are:

  • current morale of the staff
  • who has seniority
  • what skill levels that may be lost
  • what union rules may be in force if layoffs were to occur.

The improve action would be to communicate with the staff about potential impacts as soon as possible and compare the skill levels of those being cut with skill levels needed for the services that will still be offered. If the department has a union, this information would be important if a bumping process were considered.

Another AoC analyzed in figure 4 is Service Cuts. Some potential areas we would want to measure and analyze are the services we currently offer, services we are mandated to offer, and any duplication of services. The improve step would be to develop a priority list of services to be offered after the budget cut and a listing of those services scheduled to be cut. Another measure and analyze step could be to detail the impact and potential risks to the community when the services are cut.

Figure 4: Disruption and Impact Diagram

Example 2 - Disruption Caused by Server Crash

Figure 5: Disruption and Impact Matrix - Server Crash


These two examples show how the Modular kaizen Lean Six Sigma approach minimizes disruptions by making sure no "improve" is executed until "measure and analysis" have been done to establish the baseline measurement of where a disruption begins. Doing measure and analysis first helps keep the team disciplined so that no rash action is taken in an uninformed manner. When any action is taken, it is done in an informed manner. Short-term minimization of disruption can be accomplished while still supporting strategic, system wide process improvement.


[1] Modular kaizen, R. Bialek, G. Duffy, and J. Moran, Public Health Foundation, 2011, http://www.phf.org/resourcestools/Pages/Modular_kaizen_Dealing_with_Disruptions.aspx.

[2] The Essence of Modular kaizen, G. Duffy and J. W. Moran, ASQ Six Sigma Forum, as yet unpublished, 2011.

[3] Hoffherr G, Moran J, Nadler G.Breakthrough Thinking in Total Quality Management. Englewood Cliffs, NJ: PTR Prentice Hall, 1994.

[4] The tools of Modular kaizen, as listed in figure 1 are described in the full text: Bialek, R, Duffy, G, Moran, J. Modular kaizen: Dealing with Disruptions. Washington, DC: the Public Health Foundation; 2011

[5]Bialek, R, Duffy, G, Moran, J. Modular kaizen: Dealing with Disruptions. Washington, DC: the Public Health Foundation; 2011., pg. 63

[6] Note that the Force and Effect Diagram + ca is titled to represent the "check" and "act" phases of the PDCA improvement cycle. The tool is equally effective for improvement teams employing the more robust DMAIC steps of "measure", "analyze", and "improve."