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Plan-Do-Check-Act

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WE HAVE FINALLY reached the implementation phase! Many people are so anxious to “get busy” with implementation that they shortcut the previous portions of the process. This is a critical mistake! Without a clearly defined prob-lem, how would you know what you’re trying to improve and how much you’ll need to do to reach the goal? You would be firing at a target that does not exist. Without a thorough analysis, how would you know which target to shoot at? You’d see many targets (potential problems and causes) and even hit some of them. But would you achieve the desired result if you shot at the wrong target? Not likely. You would “fix” some things and know that you’ve done “good things,” but the important performance indicators would not show improvement. To avoid this frustrating situation, fully complete the problem definition and root cause analysis phases before moving into implementation.

But take heart. You will actually get to implementation! In fact for some simple problems, the entire process of thinking through the problem and its causes and coming up with a solution could be done in a single short meeting. Once you are convinced you have done a good job to this point in reaching a good solution to the right problem, there is still a bit of work to do before you charge off and move stuff around, build racks, or whatever. The famous Shewhart cycle of plan-do-check-act suggests you should start with a plan. In fact, all of the work up to this point is part of the planning. But there is still the step of developing an action plan.

Plan: Develop an Action Plan

There are numerous tools and techniques to assist in the development of an action plan, including scads of project management software. Except in the case of the most complex problems, many of those tools are overkill. A common theme within the Toyota Way is that the method or tool is not as important as the thought process and the skill of the user. The development of an action plan follows this same theme. The most important objective is to develop consistent understanding of and alignment to the plan. Resources will surely be wasted and results minimized if the plan is unclear or if everyone is not aligned to the task. Within Toyota the term “countermeasure” is used to describe the proposed solution. Toyota’s philosophy is that problems are never truly “solved.” The countermeasure merely mitigates the effect of the problem. Countermeasures are divided into two groups:

  1. Short-term countermeasures
  2. Long-term countermeasures

It’s generally understood within Toyota that most countermeasures will be implemented quickly (within a week), and therefore the definition of short term, and long term refers to the overall permanency of the countermeasure. The primary understanding is that a short-term countermeasure refers to one that is temporary, a “Band-Aid” that will provide temporary relief until a more effective or extensive solution can be implemented. In some circumstances the temporary solution becomes permanent if a more effective solution is not found. The idea is to always consider an immediate action that will provide instant improvement of the problem situation.

In the case of a quality problem, for example, if the root cause is determined to be a tooling issue, and the tooling needs extensive modification to correct the issue (a long-term countermeasure), short-term countermeasures would be utilized to both reduce the creation of defects and ensure that any resulting defects are not passed to the next process (in-station process controls and error proofing—poka yoke). In the sawing example from chapter 15 where production output was a problem and cleaning time was an important cause, a short-term temporary countermeasure was implemented to minimize lost production time due to cleaning. Temporary workers were assigned to clean during planned line stop times such as breaks and lunch. This could be done immediately, and the benefits collected, while waiting for implementation of permanent long-term countermeasures.

Effective use of both short-term and long-term countermeasures provides Toyota with immediate benefits, and at least minimal relief from the symptoms (like an aspirin), while the “ultimate” solutions are implemented. In many cases the ultimate solution is difficult, or not possible given current capability (such as the robot failure discussed in chapter 14); much time can be wasted, and benefits lost, while waiting for an “ultimate” solution. Toyota places extremely high importance on protecting the customer (the next process in the flow) from any problem. This concept makes the implementation of short-term countermeasures critical.

Long-term countermeasures are intended to permanently eliminate the root causes. Implementation timing may extend beyond a week, or beyond months. In these cases it is best to divide the task into smaller increments. This provides two benefits:

1. Smaller, bite-sized tasks provide a smaller check frequency interval. Progress toward completion can be more closely monitored and assistance provided if the task falls behind schedule.

2. The idea’s effectiveness may be tested after a small portion is completed rather than waiting until the entire process is completed and then determining that the idea was flawed.

For example, a proposal to implement a material replenishment kanban process for 2,000 individual parts is a major undertaking. The total time required may be two to three months. The team needs to analyze and determine specific design parameters regarding reorder points, container sizes, and the number of kanban required in the system. If the team analyzes all 2,000 items prior to actual implementation of physical kanban, they may discover flaws in their rationale. This discovery would occur very late in the implementation process, and many hours would be lost. In addition, no benefit would be achieved during the twoto three-month period. Essentially this is the result of “batching” the implementation instead of breaking it into a small batch flow.

Dividing the task into 25-percent segments, beginning with the 25 percent most commonly used parts (to get the greatest benefit first), would allow the team to verify their process, ensure desired results, and gain partial benefit earlier in the process. The team could provide feedback on their activity after three weeks, an intermediate check to verify that the entire task will be completed as scheduled (with additional feedback after six and nine weeks). Following these guidelines ensures Toyota immediate returns on activities, as well as verification of success for the long term.

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Dividing long-term countermeasures into smaller increments is essentially the concept of heijunka, or leveling, applied to problem solving. In production operations the larger time frame—say one month—is first divided into smaller daily increments (usually per shift). This daily requirement is segmented further into an hourly requirement, and the production result is verified each hour. In this way, adjustments can be made throughout the day, based on the checking frequency (hourly), to ensure the successful completion of the task at the end of the period (first the day, then the month). Utilization of this leveling principle for problem solving greatly increases the likelihood of producing the desired results.

At its core, a “plan” details what, who, when, where, and, if necessary, the how. Begin with the short-term countermeasures. Identify actions that will mitigate the effects of the problem (i.e., control the occurrence). Identify actions that will ensure that the effects of the problem do not affect others outside the area, especially customers.

Identify the person (not group) who will have responsibility for ensuring the successful completion of the countermeasure. The responsible person does not have to actually implement the action, but does have the responsibility and accountability to explain the plan, coordinate efforts, schedule additional resources, verify completion according to plan, and provide updates of progress.

Note that in some cases the implementation of countermeasures should be “phased,” or sequential. When attacking the root cause of a quality problem, for example, simultaneous implementation of multiple countermeasures makes it difficult to understand the effectiveness of each individual countermeasure. This “shotgun” approach may lead to success, but there won’t be a clear understanding of how the success was achieved. In the scientific method, if an experiment is conducted but the results are not repeatable, no effective conclusion can be drawn. In this case the result cannot be reliably duplicated, and future problem-solving activities will be less effective because how the result was achieved is not known.

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In many cases there’s confusion between responsibility for making sure the countermeasure is completed successfully and responsibility for actually doing the work. More complex issues tend to be assigned to “the team” rather than to a specific individual, because of the perception that the implementation will require additional people, or that the entire group wants input or involvement. This leads to lack of individual responsibility, vague expectations, and limited results. Always identify a specific person willing to take the lead role. Others may be assigned as support if necessary, but the leader assumes responsibility. At Toyota, it is always clear which one person is responsible for results. That is the essence of accountability.

The action plan (from chapter 15 wood sawing clean up case) summary is presented in Figure 17-1. Note that this is not a completely detailed plan, with actions and responsibilities developed for the team. But this level of detail is not important for others reviewing the activity. The general idea is that if the desired results have been achieved, the action plan and its execution must have been good, and understanding every detail is not necessary. (There is no need to verify the thinking process if the desired results have been achieved.)

Figure 17-1. Summary action plan

Do: Implement Solutions

Finally you can do something. You have arrived near the finish line. But you still may not be finished. It is common to implement a solution and then find, upon completion, an additional opportunity for improvement. This phenomenon occurs because it’s not always possible to see further possibilities until initial steps are taken. Imagine yourself looking at a staircase. If you look straight ahead, it’s only possible to see the step right in front of you (straight ahead). If you step up one stair, your view now changes to the next level as well. This continual climbing and revealing of the next step is the process of continuous improvement (see Figure 20-8).

Given this phenomenon, and the perpetual nature of continuous improvement, one might ask, “When is a project complete?” The answer lies in the successful achievement of the goal as established in the problem statement. If the problem is solved (as defined), the activity is officially completed. Toyota, however, will continue to make small improvements by actively pursuing all issues, at all levels, all the time (described in Chapter 13). The responsibility for sustaining the results would be passed to the people responsible for the work area. At times the solution to one problem will “create” a lesser problem, requiring a modification. The implementer must continue to observe, and to correct until the process performs as planned.

Check: Verify Results

If you’ve tested your ideas as part of the selection of solutions, you have already confirmed the effectiveness, and verification of improvement has already been done. It is only necessary to collect actual process data after the change and chart it in the same way you charted the problem. It should be evident that if results are going to be presented, it’s necessary to have a baseline for comparison to verify improvement. It is surprising to discover that in many cases data prior to “improvement” is not available! How is it possible to verify improvement if there is no point of comparison? Generally, this is due to the eagerness to rush off and solve the “problem” without fully understanding the extent. (Without data, the severity of the situation is only a subjective “feeling.”)

There are two levels of results: those directly related to the root cause being addressed and those that affect the original problem. If the root causes discovered are part of the correct causal chain, an improvement in results at the root cause level should travel up the chain using the “Therefore” method and result in improvement of the original problem, as shown in Figure 17-2.

Problem statement: The fabrication units per hour is below goal.Meet the fabrication units per hour goal!

Figure 17-2. Showing the entire causal chain

TRAP

If the process has been followed correctly, the solutions implemented will produce the desired results. Do not include “results” that are not related to the problem. For example, a discussion of improvements to the area lighting would not be relevant to the problem of not meeting the production requirement. The results presented must be directly related to the stated problem and the corresponding indicators.

The focus of the results verification should be on the high-level problems defined in the problem statement. While addressing these specific problems, unrelated benefits may be achieved. For example, the changes to the work area above will result in the reduction of floor space required. This was not a primary objective, but it provides a potential benefit that may be utilized at a later date.

Figure 17-3 shows a completed results summary.

Figure 17-3. Completed results summary

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When depicting results it is important to begin a new graph that will normally begin after you have completed analysis of the current situation. Do not simply add data to the existing problem statement graph. The dates on the graphs in the results summary section begin after the end of the Problem Statement section graphs. For example, in our situation the problem was “picked up” in December 2004 so the problem statement graph shows the problem up through December. The results were tracked beginning in February 2005. Of course, you will want to show a trend from before implementation through to implementation and then beyond to show sustained improvement.

Act: Make Necessary Adjustments to Solutions and to the Action Plan

As you can see, the entire problem-solving process is a continuous progression of developing a hypothesis, testing the hypothesis, measuring results, adjusting the hypothesis, retesting, measuring, and so forth, until the desired result is achieved. With continued practice, skills are improved and the first-time success rate will be increased. With a thorough understanding of the root causes, and the contribution of each to the overall problem, the effect of proposed countermeasures is easily predicted. Experimentation and simulation of countermeasures provide a clear understanding of the effectiveness of proposed solutions prior to any major investment of time or resources.

During this important phase it’s critical to “stand in the circle” and observe the changes that have been implemented. Watch closely to verify that they produce the desired result. It is not uncommon for a solution to create new “problems.” Sometimes these are related to people getting accustomed to the new method, and it’s important to be able to distinguish “adjustment issues” from real issues. In some cases the core problem is broken into several smaller pieces, and lesser problems surface. Continue to address these subproblems until the operation runs smoothly. (Don’t try to eliminate all problems, since that is unlikely and you could work toward that goal for a lifetime!)

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Confusing Problem Solving with Statistical Analysis When we describe the scientific method of hypothesis, measurement, and testing . . . what will immediately come to mind for some

readers is six sigma. Certainly the DMAIC methodology of six sigma is very compatible with PDCA and the problem solving method we describe here. But we have seen six sigma in the hands of novices become an exercise in statistics instead of an exercise in thinking. The problem is not well defined, months are spent carefully analyzing the wrong data, there is little go-and-see activity, and the solutions are simplistic or just plain wrong. The Toyota Way focuses on facts, most often in their purest and simplest form. As Mark Twain once said: “Facts are stubborn things, but statistics are more pliable.”

Act: Identify Future Steps

The successful completion of a problem-solving activity should be celebrated and the efforts of everyone involved recognized. Members are to be congratulated on their ability to effectively identify the problem causes and for their creativity and

exceptional thinking in developing countermeasures. This is not, however, a time for them to “sit back on their laurels.” The nature of continuous improvement means that completion of one problem-solving activity should lead to the start of another. This is a reminder that while one problem has been resolved successfully, there are many more that need attention.

At the conclusion of a problem-solving activity the “next steps” or “future steps” are reviewed to remind everyone of this process of continuous improvement. This section should address four issues in particular:

1. Describe plans for wrapping up any “loose ends” pertaining to the current activity. These are planned items that may not have been implemented yet, or items that require some modification.
2. Explain how responsibility for sustaining current results and continued improvement of the issue will be assigned and supported by the leadership of the area. This item is crucial since improvement results are often not sustained because there has been no responsibility assigned. (Responsibility is often assumed to belong to leadership, but it must be clear what they will do and how and when they will do it.)
3. Identify whether any assistance is needed to resolve any issues that are beyond the control of the problem-solving team. This may include issues with a material supplier that requires support from the purchasing department, or help from an equipment manufacturer.
4. The team, or the individual, must look forward and identify the next problem to “pick up.” This would generally be the next most important issue in the work area.

In addition to these four items, in some situations it is important to share the information from this activity within the organization to areas experiencing similar problems, or with similar processes. Generally, ensuring that information is shared would be the responsibility of management. Members of the team could provide the necessary technical experience to other groups.

Examples of possible future steps for the sawing example above are:

  • Continue improving dirt containment and control activities.
  • Implement daily 5S review by the team leader and weekly review by the group leader.
  • Develop an automatic unloading device to further reduce cycle time.
  • Improve handling to further reduce cycle time.
  • Begin an activity to correct other causes of late shipments.

Finally Some Action

The implementation phase of the process is when things finally change. It is a time to develop a plan, begin to implement solutions, and verify the results.

This is the phase most people can’t wait to get to. It can also be a frustrating time if change happens but the desired results do not follow! It’s likely you will have to train yourself and others to develop the patience and skill necessary to thoroughly evaluate the problem and carefully analyze to find the root causes. This temporary postponement of implementation gratification (don’t jump to solutions) will provide greater returns in the long run. Some key points to remember during the Plan-Do-Check-Act phase are:

  • Always consider short-term temporary countermeasures for immediate benefits.
  • Divide larger tasks into smaller segments, with assigned completion dates and measurements for each portion.
  • Responsibility for an action item does not mean that the responsible person has to do the task. They are responsible for the outcome and for ensuring progress.
  • The only way to verify results is to ensure that an effective measurement process is in place prior to implementation so that a before and after comparison can be made.
  • Once your solutions become a reality, it will probably be necessary to make adjustments. Follow genchi genbutsu, and carefully observe the new process to verify that it is free from major problems.
  • Always conclude your process with a look to the future. Continuous improvement means forever! Set the expectation that the process of improvement is never complete.

Reflection Activities

Many people mistakenly place a high importance on the “action” phase of problem solving. It is thought that “making things happen” is the most important step in getting results. In fact, the most important step in getting exceptional results is in effectively identifying the root causes. If you have identified the root causes, the necessary corrective actions should be clear, and when implemented will produce the desired result. Take your time to ensure that the correct root causes have been identified prior to beginning the corrective actions.

1. Evaluate performance results in your organization. Do they show the desired improvement resulting from your problem solving activities?

2. Evaluate recent problem-solving or continuous improvement activities to determine the overall effectiveness.
a. Do you find that many items are implemented but the desired results are not achieved?
b. What part of the process is being missed that causes this situation? Look specifically at whether the problem was clearly identified and root causes were determined, or whether people just started “shooting” at the problem.
c. Were both short-term temporary and long-term permanent solutions used appropriately?

3. For the problem you’ve been working on, complete the following activities:
a. Make sure that defined results are predicted for each action item. This includes the specific measurement and amount.
b. Develop an action plan that includes both shortand long-term countermeasures as appropriate.
c. If the solutions require significant effort, break the activity down into quartiles, with specific actions and expectations for completion during an incremental time period. For example, a one-month activity can be broken down into 4 one-week portions each having a defined expectation for completion.
d. Clearly define who, what, when, and if necessary how each action item is to be completed.
e. As part of your action plan, define who will support the transition from the old way to the new way. Someone needs to be in the work area during the change to ensure a smooth transition.

4. Prior to implementation, determine how the effectiveness of each action item will be measured.
a. Verify that a preimprovement baseline measurement is completed.
b. Determine a measurement process and verify that results are being captured correctly.
c. Chart the results in the work area and review with everyone regularly.
d. Monitor the process regularly and determine whether adjustments to the plan are necessary (if you are not getting the planned results).

5. After the problem-solving process is “completed” (continuous improvement implies that improvement is never complete, but at some point you move on to other issues), identify appropriate future steps.
a. Complete any outstanding items from the action plan.
b. Develop a plan for sustaining the results. This includes those who will have direct responsibility for sustaining the results daily.
c. Identify whether additional support will be needed to fully correct the issue being addressed. Arrange for the necessary support.
d. Evaluate other problems, and determine which will be the next to be corrected. Make plans for correcting these issues.