The Toyota Way Fieldbook phần 8 doc

Careful consideration must be given to understanding the characteristics of the problem—by weighing the impact of the problem on customers,employees, and the company, and finally by deci

Carefully Aim Before Firing

In Toyota’s internal Toyota Way 2001 document they describe problem solving

under the broad category genchi genbutsu—the actual part, the actual place The

discipline of carefully observing actual processes directly without tion—with a blank mind—starts the process of truly understanding the problem.This leads to a thorough explanation of what is happening and its effect on thearea, the team, the customer, or the company and reveals why the problemdeserves attention The first requirement of problem solving is to determine themerit of solving the problem At this stage, all problems can be weighed side byside, and the most important are tackled first Lesser problems may be assigned

preconcep-to small teams, such as Quality Circles, or even preconcep-to individuals

There’s a saying that mocks both American and Japanese styles of problemsolving The Americans say, “Ready, fire, aim,” while the Japanese say, “Ready,aim, aim, aim, fire.” There is an element of truth in both of these approaches, and

an element of both strength and weakness in each

Many companies in the United States are so focused and driven by short-term(quarterly) results that improvement activities are initiated before the situation

is clearly understood These actions are completed, and a new (90-day) plan is

Develop a Thorough

Understanding of the Situation and Define the Problem

Chapter 14

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developed each quarter This short-term “fire first and set the target later”approach leads to a “shotgun” effect, resulting in bits of improvement here andthere Often these random improvements are made to issues unrelated to thesituation being addressed Activities are completed, but the desired condition isnot achieved, and because there was no defined reason for these activities, along-term sustainment of “results” is virtually guaranteed to fail.

In contrast, the Japanese (and Toyota) can be painstakingly meticulous inthe initial phase of understanding the situation, which frustrates Americanswho are ready to “get started.” This apparently belabored process is vital to asuccessful problem-solving activity for two reasons

1. Careful consideration must be given to understanding the characteristics

of the problem—by weighing the impact of the problem on customers,employees, and the company, and finally by deciding if the problem isimportant enough to dedicate valuable time and attention to solving Theinventor Charles Kettering said, “A problem well stated is a problem halfsolved.” Put another way, a large proportion of the problem-solvingactivity should be devoted to thoroughly understanding the problem sit-uation, which leads to focusing on the problem rather than its symptoms

2. Focusing energy and leveraging resources is critical to achieving a higherlevel of success with minimal effort This starts with reaching agreementwith all affected parties on the need to pursue the issue

Within Toyota, the question, “Why did you pick up this problem?” is oftenused It means, “How did you determine that this problem deserves your timeand attention?” And also, “Why did you choose this problem over the manyother possible issues?” In addition, there is an implied request: “Please explainyour reasoning so I can understand the situation, ensure that you’ve done ade-quate reflection, assure that we are in agreement and alignment on the issue—and so I can provide necessary support and guidelines for your process.” Thereare many things packed into that one simple question, issues that must beexamined in order to develop a thorough understanding of the situation

TRAP

Avoid the mistake of putting too much effort and expense intosolving insignificant problems Carefully consider the importanceand value of solving the problem prior to beginning activity Donot exert one dollar’s worth of effort to solve a five-cent problem

If the problem is relatively minor in comparison to other lems, it can be addressed by the individual or team most affected

prob-by it, rather than prob-by a large team or member of management

This rigorous questioning often leads to frustration for Americans, whotend to feel that it questions their ability to handle the situation on their own (anAmerican characteristic), or that their evaluation was not complete WithinToyota, many people meticulously review the process of understanding the sit-uation, and feedback is always given Often, after initial rounds of questions,additional rounds of questioning ensue This is the “aim, aim, aim” phase.Valuable insights can be gained by this repetition, perhaps bringing new things

to light through various reviewers, and in the long run much time can be saved

by not chasing errant issues of lesser importance

If your organization hasn’t had an effective process for making improvement,there will probably be numerous issues in the backlog When the word “problem”

is mentioned or people know that you want to improve processes and are ested in knowing what the problems are, two things will probably happen:

inter-1. You’ll be deluged with many problems, ranging from broken water tains and fans (which should be corrected without the need for long-termproblem solving) to issues that occurred years ago

foun-2. As soon as any “problem” is mentioned, solutions will be proposed Sincethe existence of a problem has not been confirmed, any proposal of solu-tions is premature and a waste of time (not focused or leveraged).Initiating this process may be like opening Pandora’s box After lookinginside, you may wish you had kept the lid closed! It’s easy to be overwhelmed

by the magnitude of opportunity for improvement available (and necessary)and the sheer numbers of problems that will surface

TIP

You must be prepared to help people differentiate betweenissues that can and should be corrected in the short term withoutin-depth analysis and long-term endemic issues that affect theperformance of the person, group, or company

TRAP

One of the signs of a “Ready, fire, aim” culture is the tendency to

“jump” immediately from the “problem” to the “solution.” In manycases the problem may be mentioned casually and much timespent proposing various “solutions” before the “problem” hasbeen clearly defined At this stage in the process it is likely that

a symptom has been observed rather than a true problem

The following is a typical conversation that might occur, indicating the trap

of jumping to solutions prematurely:

Manager: We have been having trouble with defects lately (Note the vague

sation gets way off track!)

Employee 3: Do you know what happened to it?

Employee 1: No, but I know he had one.

Employee 2: I saw it too, but I’m not sure what happened to it I think he told

the engineer, but nothing was ever done

Manager: Would you ask Joe to find out about his design and see if he still

has it? (Now valuable time will be wasted chasing a “solution” to an fined problem.)

unde-Employee: Yes, I should know something by next week’s meeting.

Problem solved! Or was it? What was the problem? “Defects” is a fairlybroad issue Why did the employee jump to the conclusion that “defects” werecaused by handling? That may be his personal experience regarding “defects,”but it’s only one possibility Do you see how the process was so easily side-tracked? The conversation went from a general statement about defects (not awell-defined problem), to a cause (handling), to a solution (Joe’s carts), to anaction (follow up with Joe) in a matter of seconds What will happen next?There will be follow-up with Joe, additional meetings when time is spent (wast-ed) debating why Joe’s solution was never used in the first place, and thendebate about whether it was actually a good design and a different design isneeded Finally, a decision may be reached to build new carts, and they will beput in place Do you think the “defect” problem will be resolved? The sad part

TIP

To avoid premature discussion of solutions and to keep theprocess on track, record ideas for solutions with a statement suchas: “Okay, that may be a possible solution and I don’t want tolose your idea, so I’ll write it down and we can discuss it later,when we’re investigating possible solutions However, rightnow we want to stay focused on identifying the problem.”

is that this group is under the illusion that they’re actually getting “results,” and

in fact they may somewhat improve the results But it’s a case of focusing on thenickels (small causes) while the dollars (major causes) fly overhead

Find the True Problem to Get the Most

prob-in purchasprob-ing often believe that vendors are the primary concern, and engprob-ineerstend to focus on equipment-related issues

Toyota refers to the Five-why process (explained later) as a “causal chain,”because the problems and their causes are linked together in a series of singleand branched chains In an attempt to identify “the problem,” people often enterthe causal chain at the problem perception point, or the “point of recognition,”rather than at the level of the true problem They have identified what theybelieve the problem to be, but they may be further down the causal chain ratherthan at the top, where the true problem resides Finding the true problem isbased on understanding its effect at the highest level, where the full impact ofthe issue is experienced

When identifying any problem, Toyota views it in the context of the primaryperformance measures, which are safety, quality, productivity, and cost (Figure14-1) These measures are inherently linked to one another, and it’s not possible

to negatively impact one of the measures without also negatively influencinganother For example, if a defect affects quality performance, it may also affect

TRAP

It’s easy to confuse activity with results A poorly defined problemand a rush to solution and action lead to activity without achiev-ing the desired results If you desire to maximize your return, afocused effort on a clearly defined problem followed by a thor-ough analysis will lead to significant results

the ability to produce the desired quantity of product, thus causing customerservice levels to suffer To avoid affecting the customer, appropriate countermea-sures such as increased inspection or production time may be employed to protectthe customer These extra measures will increase the cost An operator who detectsthe defect may conclude that the defect is “the problem,” when in fact the trueproblem is the affect on customer service, and ultimately on the total cost.

The placement of the measures in this model does not imply importance Inother words, cost is not the most important measure Customer satisfaction isthe most important measure We want to achieve the highest level of customersatisfaction while maintaining the lowest possible cost

Delivering a quality product to the customer is always understood to be thenumber one goal A tenet of the Toyota Way is that a defect should never knowingly

be passed on to the next process The effort to ensure the correction, containment,

or control of the quality problem will have a negative impact on productivityand cost Notice the lack of “customer delivery” or “safety.”

Within Toyota, all processes are closely linked to each other, and the tomer” is actually the next process Given these tight connections and the fact

“cus-that all processes in the plant and throughout the entire supply chain are

inher-ently linked, if you fail to meet the customer demand (the next process), the

entire operation will begin to stop, one process at a time (like dominos) For this

reason, the satisfaction of the customer is implicitly understood and does notneed to be measured separately If a process is unable to meet the demand, it is

a productivity issue In addition, safety is an implicit expectation for everyone,and as such, may be “omitted” from the discussion of measures Safety as thenumber one priority is a given

COST

CUSTOMER SERVICE

QUALITY PRODUCTIVITY

Figure 14-1 Relationship of primary performance measures

It may helpful to think of these relationships in terms of the problem, toms of the problem, and the causes of the problem

symp-Using a medical condition as an analogy: Suppose you visit the doctor andcomplain of aches and fever These are not the problem They are symptoms ofthe problem The problem is that you don’t feel well (and as a result may misswork or other activities) The doctor will take information and perform testsand gather facts (vital signs) that are part of the analysis, to find the cause of theaches and fever Visually, the process looks like Figure 14-2

Symptoms are presented to the side of the problem, as in “I have this problem,and as a result I have these symptoms.” To get to the cause(s), the information

is analyzed to evaluate all possibilities The symptoms are an important piece inthe overall understanding of the problem They provide supporting evidencethat a problem exists They also provide quantifiable data showing the magnitude

of the problem In this case, a fever of 104 degrees is more significant than afever of 100, thus increasing the need to treat the problem

The relationship of the three primary measures will follow the same model

of Problems, Symptoms, and Causes, as shown in Figure 14-3

In this case, low productivity would be the problem, poor quality a cause, andhigh cost a symptom or result Using this model is important because it forces con-sideration of the bigger picture We may believe that a repetitive quality problem

PROBLEM

(Don't feel well)

AS A RESULT OF THE PROBLEM

is the true problem, but if we look further, we find there is an issue having a greaterimpact (this is assuming that the rule to never knowingly pass a defect to the nextprocess is followed) Quality is a causal factor for poor productivity.

This thought process is depicted in Figure 14-4 The problem is perceived at thepoint of recognition (where the problem is “found”) To consider this “problem” in

a larger context, we would use a statement such as; “We have this problem, fore, this happens.” For example, suppose that the perceived problem is a machinemalfunction resulting in scrap parts The statement would be, “The machine mal-functions, therefore the part is scrap.” Continuing this line of thinking we state,

there-“The part is scrap, therefore we are losing production capacity and increasing cost.Therefore, we are not able to meet the production requirement,” or, “Therefore ourcost it too high.” At this point we begin to understand the greater significance ofthe true problem

If we do not consider the situation in a larger context, we may limit the sible solutions as well and the total impact of solving a larger problem Thinking

pos-in this way allows us to identify the true problem and thus provides three distpos-inctadvantages:

1. Ensuring that the most significant opportunity has been captured mizes results with minimal effort

maxi-PROBLEM

AS A RESULT OF THE PROBLEM

SYMPTOMS:

Poor Customer Service

2. Taking a larger view opens the possibility of solving the true problem bycorrecting causes in addition to the ones initially identified

3. The lower-level cause identified may be very difficult to correct (which iswhy it is perceived as the biggest problem), and focusing only on this dif-ficult condition will preclude consideration of larger and easier causes,which lead to greater opportunity

The following was an actual conversation between a Toyota sensei (teacher)

and a process engineer at an automotive parts plant It examines the challenge

of shifting focus from the perceived problem to the true problem

Sensei: What is the problem in your area?

Engineer: The welding robot keeps breaking down (The perception of the

“problem” is based on personal experience and the person’s role.)

Sensei: Are you sure that is your problem?

Engineer: Yes It breaks down all the time We’ve tried various things to correct

it but have had only limited success We need to get a new robot (Noticethe jump to a solution.)

Sensei: I am not sure that is your real problem.

Engineer: Yes it is It has been the problem for a long time We have data to

show how much it breaks down

True Problem

Point of Recognition

Point of Cause (Where the problem physically occurs)

Exploration of the

perceived problem may

lead to discovery of a

Larger Problem

Solving a Larger Problem

may yield different

opportunities for solution

Therefore….

Moving towards understanding the True Problem

(The "perceived problem")

Sensei: I am sure it breaks down, but I am still not sure it is the real problem Engineer (a little angrily): It is the problem I’ve been working on this for

almost four years and I can tell you it is a problem (Is it the problem or aproblem?)

Sensei: Yes, I know you’ve been working hard on the robot; however, let me

explain why it is not the real problem When the robot breaks down, whathappens?

Engineer: There is a fault at Loading Zone 3 because the weld nut does not

feed We’ve been working with the vendor to improve the feeder

Sensei: Okay, what I mean is, what happens to the line when the robot breaks

down?

Engineer: It stops, of course.

Sensei: When the line stops, what happens?

Engineer: Everyone stands around, and they call me to fix the robot.

Sensei: I mean, what happens to the flow of product?

Engineer: It stops.

Sensei: When the product flow stops, what happens?

Engineer: Everyone stands around.

Sensei: I mean, what happens to our ability to make parts?

Engineer: Of course we can’t make parts with the line stopped!

Sensei: So we are not able to satisfy our customer with the required number

of parts?

Engineer: We can’t meet the demand without working overtime.

Sensei: So the real problem is that we are unable to meet customer demand

without working overtime?

Engineer: No The problem is the robot.

Sensei: Well, let’s go to the line and look.

As the sensei and engineer proceed to the line, the engineer wants to takethe sensei to the robot to show him the “problem.” The sensei knows that linestoppage for any reason will ultimately affect the ability to meet production

demand and that the robot is only one possibility Therefore, it is further down

the causal chain and not the high-level problem he’s looking for The senseitakes the engineer to the end of the line to observe flow In a few minutes henotices that the flow stops

Sensei: Why did the line stop?

Engineer: The employees are rotating positions.

Sensei: How often do they rotate?

Engineer: Every half hour, but you can’t change that without causing a large

problem with the employees They all agreed on a half-hour rotation forergonomics

Sensei: My concern in not how often they rotate I am concerned that when

they do rotate, the line stops for about four to five minutes That is as much

as 10 minutes every hour, nearly 20 percent lost time!

They watch the line a little longer and again the flow stops This time it isbecause the shipping container is full and waiting for the material handler toremove it and bring an empty one

Sensei: Why did the line stop?

Engineer: The container was full and they needed a new one The only way

you’re going to prevent that is to have a material handler here full-time,and we don’t have enough material handlers for that

Sensei: (Sternly) There is always more than one way to solve any problem.

I’m sure we can design a system for exchanging the containers in a waythat does not stop the product flow and does not require a material han-

dler here full-time Right now, though, I am just trying to understand the

true problem

Here is how the causal chain appears to the engineer:

Problem: The robot breaks down

Why? There is a run fault signal in Zone 3

Why? The nut does not feed

Why? The equipment is not designed correctly

Where does this path lead? It leads to a dead end! It is a dead end that canconsume large amounts of time and money attempting to correct a very chal-lenging issue In the meantime, the “low hanging fruit” is falling from the tree!

Examining a Problem in Reverse

Now let’s look at the causal chain from the sensei’s point of view First, he beginswith the problem as pointed out by the engineer, and using the “therefore”method, he proceeds back up the chain until he’s sure he has found the true prob-lem, as shown below Note that we begin at the perceived problem line and con-

tinue to state “therefore” proceeding upward until the true problem is identified Therefore: The process can’t meet demand without overtime This is the true problem.

Therefore: Process doesn’t make parts

Therefore: The product flow stops

Therefore: The line stops.

The robot breaks down Start with the perceived problem and work up tofind the true problem

Once the true problem and resulting symptoms are identified, it’s possible

to compare the full implications of the true problem and consider the value ofproceeding with the process of solving the problem It is still necessary to definethe extent of the problem and its characteristics

Defining the Problem

In order to be defined as a “problem,” four pieces of information are required:

1. The actual current performance with some historical trend detail

2. The desired performance (standard or goal)

3. The magnitude of the problem as seen by the difference between the actualand desired (sometimes referred to as the “gap”)

4. The extent and characteristics of the problem or situation

When presenting this information, a picture is worth a thousand words.Always try to explain the situation visually with a trend graph (Figure 14-5) Thetrend graph should include enough historical data to show how long the condi-tion has existed (for long-term performance improvement opportunities a mini-mum of six months is recommended if available) The data should be displayed

so the characteristics of the problem are seen For example, does the problemappear to be getting better, worse, or staying the same? This understanding assists

in determining the importance of addressing this problem versus other lems If the problem is getting worse, more immediate action may be necessary,such as a short-term countermeasure If the situation is getting better or staying

prob-Monthly Units per Hour Fabrication Line

0 10 20 30 40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Goal = 36

Figure 14-5 Trend chart of monthly units per hour

the same, the future results are more predictable (not likely to get worse) and theconsequences of inaction (which is always a considered action) are understood.The goal is to portray the situation so an accurate assessment is possible.This is best achieved using actual facts and not assumptions or “feelings.” Be wary

of data coupled with the words “I think” or “ I feel”! The goal is to elevate problemsand to get a clear understanding of their characteristics so we can understandwhat will be required to solve them and how difficult that will be A problemthat’s stated in a way that makes it look better than it truly is does not help inthe problem-solving process (Figure 14-9)

Also consider the stability of the problem Are the results consistent day-to-day(or period-to- period), or are there large swings with varied good and bad results?Problems with a high degree of variation from period to period indicate a situationthat is out of control There are probably many contributing factors, and isolatingthe causes may be difficult An intermittent problem is also harder to analyzebecause it does not occur consistently, and therefore seeing the problem firsthand

is difficult and often requires an extended observation to identify the causes.The charts in Figures 14-6 to 14-11 were generated using the Microsoft Excelcharting function (primarily for ease of printing) Excel will automatically selectscaling based on the high and the low data points and the variation In most casesthis scaling is effective for visually understanding the problem Often the data iscollected and charted manually (which is preferred by Toyota) and the scale isestablished incorrectly The charts show some common situations encounteredwhen charting data to develop a thorough understanding of the problem The chart in Figure 14-6 has an insufficient number of data points In thisexample, it is not possible to get a clear understanding of the trend Usually weneed to see 6 to 12 months of history to gain a clear perspective of the trend of

an issue For the trend, a monthly summary (average) of results is preferred toshow the higher-level, long-term direction of the problem

Monthly Units per Hour Fabrication Line

0 10 20 30 40

Figure 14-7 shows the detail necessary to understand the daily tics of the problem The performance of this fabrication process varies from day

characteris-to day within a range This process has not reached a level of stability, and thevariation indicates the possibility of multiple issues contributing to the instabil-ity, thus representing a more challenging problem to solve

Fabrication Daily Units per Hour

0

5 10 15 20 25 30 35 40

Date

Goal = 36

Figure 14-7 Chart with sufficient date points to see trend

Figure 14-8 Chart with inflated appearance of variation due to scale

Figure 14-8 shows the same data as Figure 14-7 but the variability of ance is artificially inflated due to a compressed scale on the chart Visually, theproblem appears larger than it truly is It’s important for a chart to have the correctvisual impact so everyone has a clear understanding of the challenge ahead

perform-Figure 14-9 shows the same data as perform-Figures 14-7 and 14-8 Notice how thevariation is visually smoothed This process appears more stable, and thus ismisleading An excessively large scale causes the artificial smoothing effect

Collecting data is an important part of the philosophy of building a culture

to stop and fix problems, as described in Chapter 8 The greatest benefit isgained by recognizing problems in “real time” and correcting them immediately.Data used to solve problems is interpreted from the perspective of long-termtrends and resolving “systemic” issues

Building a Strong Supporting Argument

As shown in the above examples, there will be symptoms that go along withproblems In the case of businesses, the symptoms will be reflected in confirming

Fabrication Daily Units per Hour

0

20 40 60 80 100 120 140

1/1 1/8 1/15 1/22 1/29 2/5 2/12 2/19

Week

Goal = 36

Figure 14-9 Chart with artificially smoothed variation due to scale

Figure 14-10 Chart with artificially smoothed variation by averaging

The chart in Figure 14-10 shows the effect of smoothing by averaging dailydata on a weekly basis The visual impact is lessened, and the daily variabilityinherent in this process will not be seen, thus giving a false sense of stability inthe process

performance indicators For example, an inability to meet customer demand willalso be reflected in additional overtime, missed or late shipments, or increasedbacklog These corresponding indicators provide supporting evidence of thevalidity of the problem and the merit of correcting it

Toyota uses the corresponding indicators to support the process of focusing

on the most important issues Problems are evaluated to determine which requirethe most immediate attention using the following criteria:

◆ Importance. How important is the problem in the overall context of tomer satisfaction, departmental, or company goals? Safety problems areautomatically the highest-level importance

cus-◆ Urgency What deadlines are dependent on the resolution of the problem,and what is the consequence if the deadline is not met? The ability to meet

a change in a customer requirement deadline is considered a high urgency

◆ Tendency Is the problem getting worse, improving, or staying the same?When comparing problems it is necessary to consider whether every prob-lem should be addressed

By showing the effect of a specific problem on customer service, quality,

safe-ty, or cost, it is possible to develop a compelling argument to correct this specificproblem versus other problems This method of prioritization ensures thatresources are focused appropriately on the most important and valuable problems Following safety concerns, problems that negatively affect the customertake precedence This could include missed shipments, late shipments, andquality problems Cost issues can easily be compared to ensure that the largerissues are being handled promptly The Toyota Way necessitates building astrong rationale for attacking any problem If a strong rationale has not beendeveloped, the question “Why did you pick up this problem?” would surely beasked The format for showing the supporting indicators is the same as theproblem symptom model above

A complete example of a problem statement is shown in Figure 14-11 Notethat the summary statements, along with the graphs, are sufficient to thoroughlyexplain the problem situation and the corresponding issues In this example thepictures tell the story and brief explanatory statements are used Here, the trueproblem is the inability to meet the production requirement As a result, overtime

is used to compensate for the problem (increasing cost), and customer service is

also declining The problem with its supporting evidence allows us to “size up”this problem and determine the benefit if it is solved (and also determine a sen-sible investment to make in the solution that will provide a good return on theinvestment of time and expense)

Now that the problem and the effect of the problem on other performanceindicators is thoroughly understood and a decision is made to correct the sit-uation, it’s time to develop a deeper understanding of the causes of theproblem

1 DEFINE THE PROBLEM SITUATION

Problem Summary Statement

• Units per hour is consistently below goal.

• Condition is worsening.

• Overtime costs are increasing.

• Number of late shipments are increasing.

Monthly Units per Hour Fabrication Line

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Units per Hour

Goal = 36

Overtime $ per Month

0 20 40 60 80 100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Monthly Late Shipments

0 20 40 60 80

Figure 14-11 Complete problem statement

Reflect and Learn from the Process

Identify and select a problem you want to solve and use to reflectupon in Chapters 14 through 18 The problem should be signifi-cant, but not one of the most difficult problems you have We sug-gest learning the problem-solving process on simpler issues beforetackling more difficult ones

1. Gather facts related to the problem and define the problemaccording to these criteria:

a. Display the actual performance history (at least six months)

in a line graph format

b. Show the goal or standard (current and/or in the future)

c. Identify the gap between the actual performance and thegoal

2 Consider the information that you believe depicts your problem

a. Are you sure you have identified the “true problem”?

b. Can you make a connection directly to a safety, quality,delivery, productivity, or cost performance measure?

3. Clarify the significance of solving this problem

a. Identify other issues related to this problem (items affected

by this problem) Quantify them by graphing them

b. Can you verify that it is important to “pick up this lem”?

prob-c. Quantify the value of solving this problem (don’t spend

a dollar to solve a five-cent problem)

d. Is it worth your time or the time of others to solve thisproblem?

e. How much do you want to invest in solving this problem?

4. Based on your value quantification in the previous question,determine the most cost effective method to proceed with theproblem

a. Will you “work the problem” personally?

b. Will you delegate the problem to others and only followup?

c. Will this problem require a large team, small team, or asingle individual to solve it?

TOYOTA’S CORPORATE slogan is “Yoi shina, yoi kangai,” which means, “Good

thinking, good products.” This applies particularly well to the analysis portion

of problem solving Toyota places high value on the ability to think logicallyand creatively because a solid thinking process will produce the best results.Every Toyota manager understands, above all, the value of human creativity—that it is the single thing that will set them apart from their competition.The analysis phase of problem solving should be an exploration into areaspreviously not understood It’s a bit of detective work, a bit of scientific exper-imentation, and an opportunity to discover new things Analysis is the “Ah-ha”stage, the time to gather evidence, the time to repeatedly ask “Why?” and to findthe source of an issue, its root When the root causes are discovered, the

“answers” to solve the problem become obvious At this time “good thinking”will generate the best solutions—highly effective, simple yet elegant, and lowcost, but not shoddy

As Albert Einstein once said: “The important thing is not to stop questioning.”

Principles of Effective Analysis

Effective analysis is crucial for finding and understanding the many potentialcauses of the problem From those potential causes, it’s necessary to narrow thefield and focus on the most significant ones Much of Toyota’s great successstems from the ability to fully analyze a situation and understand the many

causes of the problem beyond the most apparent The following principles are

a crucial part of the Toyota approach:

1. The analysis must not be clouded by preconceived ideas of the problemcauses If the cause is assumed, it will preclude a useful analysis and mostlikely lead to poor results

2. Always follow the genchi genbutsu principle to verify the source of the

prob-lem Do not depend on others, or on data, to find the cause Use tion to point toward the location to “go see.” The point of cause must beobserved firsthand

informa-3. Analysis is continued until it is certain that the true causes, or root causes,

of the problem are discovered (using the “Five-Why” method)

4. In nearly all situations there are multiple causes for problems, and thusthe analysis must be comprehensive Toyota evaluates causes through the4Ms: Man, Method, Material, and Machine

5. Since there are many possible causes, it’s necessary to narrow to the mostsignificant ones Narrowing allows the focusing of efforts to generategreater results

6. During the analysis, the goal is to identify problem causes that can be rected by the problem solver This avoids the tendency to defer the problem

cor-to others and forces the question, “What can we do?”

7. A thorough and complete analysis will yield root causes that will clearlyindicate specific, corrective actions There is an observable and obvioustrail leading from the problem to the causes and to the solutions

8. Thorough and complete analysis provides factual data, allowing preciseprediction of potential results when the causes are corrected Determiningthe exact result is an important part of the process since it forces the evalu-ation of capability and effectiveness in examining a problem

As with many aspects of the Toyota Way, the thought process is critical tosuccess Notice that during the following conversation, people will jump to pre-conceived conclusions rather than recognizing the simple but true answer to thequestion Using the example in the problem statement below, we would beginthe Five-Why process as follows:

Problem statement: “The fabrication units per hour is below goal.”

Upon asking our group “Why?” we might get the following answers:

1. Because the machines break down

2. Because operators are absent

3. Because we run out of parts

4. Because operators are not trained

5. Because the setup times are long

Each of these answers may be “true,” as in the conversation between theengineer and the lean sensei described in chapter 14, but they are further down

Chapter 15 Complete a Thorough Root Cause Analysis 343

TRAP

In many cases we see people attempting to force the Five-Whyprocess into five boxes by trying to “figure out” the correct chainwith five “answers.” This process does not fit a predevelopedtemplate format The causal chain may branch at any level andyield unknown quantities of answers at each If you are strug-gling to find Five Whys, most likely you’re jumping across links

in the chain Take time to reflect on the simpler, more obviousanswer in order to allow the discovery of all possibilities

the Five Why chain The first challenge is to focus solely on the direct question:

“Why are the fabrication units per hour below goal?” Then the true answerwould obviously be: “Because we do not make enough parts each hour.”Knowing where to focus is crucial in order to train our minds to understand the

complete chain Skipping what appear to be obvious links in the chain will cause

jumping to preconceived causes, thus overlooking other possibilities This isone of the greatest risks and also the greatest challenges in thinking

Proceeding with our questioning, we would ask, “Why don’t we make enoughparts each hour?” Again the tendency is to skip to the obvious answers, but byapproaching this with a different thought process, we would see this answer:

“Because we lose opportunities to make good parts.” The production of any uct is accomplished by utilizing the time of people and machinery, and availablematerial In this case there are only two main causes for a shortage of produc-tion—loss of time and loss of material (scrap) Note that this line of thinkingalso maintains a narrow focus that will isolate the most significant causes fromthe less significant ones In the example above, the first question led immedi-ately to a lengthy list Once a long list is established, it’s extremely difficult tonarrow the focus It is much easier to maintain a narrow focus and divide thepossibilities gradually through effective questioning At this point the Five Whychain would look like Figure 15-1

prod-Problem statement: The fabrication units per hour is below goal.

Figure 15-1 Initial Five-Why analysis

At this level the Five-Why chain has developed the first branch Prior to ing “Why?” for both branches, it’s important to understand which is the mostsignificant This understanding will maintain a narrower focus For the sake ofthis demonstration, we will assume that the data show that scrap is very lowand time is the greater loss, and proceed to show the continuation of the causalchain from this level It is imperative to actually confirm the overall impact ofeach item, rather than to assume The scrap quantity data may be available andfairly easy to quantify; however, the time losses will require a visit to the work-place (genchi genbutsu) to verify the amount of time loss

ask-When asking “Why?” do not jump down the chain to the deeper issues.Carefully consider the loss of time in a production process and try to keep thefocus narrow by answering the direct question Look for the broad categoriesunder which the detailed answers will fall Remember to use the “Therefore”method if you find yourself answering further down the chain If the answer

“Setup time is too long” arises, state “Therefore” and find the answer In this uation it would be: “Therefore the machine is not running for a long time.” Thefollowing step would be: “Therefore we are losing time.” If the “Therefore”method was used on some of the other issues, it’s likely that “The machine isnot running” (or “The line is not running”) would be a consistent theme This

sit-is the common category we are looking for In addition, our questioning maylead us to understand that loss of time due to excessive process cycle time isalso a primary category Now the Five-Why chain will appear as shown inFigure 15-2

Again the causal chain is branching At this time a visit to the workplace isabsolutely necessary In order to improve your observation ability you mustlearn to “look with intention.” Based on the analysis thus far, what is the inten-tion of your observation? The intention is to look to see whether there are cycletime losses or situations during which the process is not operating

The general thinking within Toyota is to consider the cycle losses first Cycletime losses are those losses that occur every cycle as the operation is performed;

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

(Not most significant)

Cycle time losses Process not running

Figure 15-2 Second pass Five-Why analysis

therefore, they have a “high tendency” of occurrence The cumulative effect ofthese small losses can be very great In addition, the reduction will generate animmediate and continuous payback A small payback that can be capturedimmediately and will continue to pay forever is a preferred result Small cycletime losses are also generally easy to correct They may include excessive oper-ator or machine motion, delays due to waiting, or overprocessing (doing more

than necessary) Of course, these are all forms of muda (waste), and the removal

of muda is a primary objective

Visiting the workplace, you will probably see many other examples of cyclelosses and process stoppages You’ll need to gather facts to understand the totalimpact of each issue—the importance, urgency, and tendency—and a simple way

to do this is to use a value-added/non-value-added1breakdown list as shown inFigure 15-3 The example is from a sawing operation, but the list generated is fair-

ly typical in most manufacturing operations Remember, the links of the causalchain were related to losses of time, either through cycle losses or due to losses oftime when the operation is not running or not adding value The list that is gener-ated will include both cycle and run-time losses Since the ultimate objective is tofind causes that are linked through the causal chain to the original problem, we’relooking only for those activities that take time away from the value-adding task

In other words, if the operator is performing a non-value-adding task but themachine is adding value while the operator does the task, improving this item willnot lead to reducing the problem, and thus is not a beneficial improvement Thefirst priority is to address the issues that directly reduce the time available to addvalue and therefore cause a loss of production

Load saw Unload saw Change blade Clean up Break down Inspect parts Move finished parts Meetings

Waiting for wood Handling wood

Blade is cutting wood

Value-Added Task Non-Value-Added Task

ALL ACTIVITY OTHER THAN CUTTING WOOD IS NON-VALUE- ADDED ACTIVITY

Figure 15-3 Value-added/Non-value-added analysis

For further information on the case see: Bill Costantino, "Cedar Works: Making the Transition to

Lean," in J.K Liker (ed.), Becoming Lean, Productivity Press, 1997.

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

Losing time Losing parts (scrap)

(Not most significant)

Root Causes Figure 15-5 The narrowing and focusing process

Seeking Problem Causes That Are Solvable

During any process of analysis there will be a tendency to jump to mined causes Predetermined conclusions are often based on issues that are not

predeter-Continuing with the causal analysis (Five-Why) process in this examplerevealed the chain in Figure 15-4 Follow the bold text chain to the root cause inthe outlined box

Toyota uses this process of continually narrowing, isolating (using the 80/20rule), and focusing efforts on the items that will provide the greatest benefit.Continuing to dig until the root causes are discovered also provides causes thatare both easier to improve and, when improved, will solve the original problem

We can think of it as a funnel as shown in Figure 15-5