Problem Analysis

Quick reference

• 00:05 Hi, I'm Ray Sheen.
• 00:06 Well, it's finally time to enter into the Analyze stage of our
• 00:10 Lean Six Sigma project.
• 00:12 Now to do this, let's start by clarifying some aspects of the problem-solving
• 00:16 process that we are using.
• 00:18 The Lean Six Sigma methodology is a problem solving methodology.
• 00:24 If there's no problem, well, then there's no reason to do the project.
• 00:28 Lean Six Sigma does not follow the lucky guess approach to solving a problem.
• 00:33 Rather relies on understanding the details concerning the problem in order to
• 00:37 determine what type of solution will work to actually solve the problem.
• 00:42 This type of problem solving method requires both inductive and
• 00:45 deductive reasoning.
• 00:46 We use inductive reasoning to take a specific observation and
• 00:50 generalize that into a theory of the problem.
• 00:53 And we use deductive reasoning to take a general theory and
• 00:57 test it with specific results and observations.
• 01:00 Most problem solving methods used in business today, and
• 01:03 that includes the Lean Six Sigma methodology.
• 01:06 Rely on a combination of both operational systems analysis and
• 01:10 mathematical data analysis.
• 01:12 That's why Lean Lean Six Sigma uses both the value stream map,
• 01:16 to understand the system and collects data for statistical analysis.
• 01:20 While we intend to be methodical and logical, we can still apply experience and
• 01:24 judgment to guide our analysis.
• 01:26 That is often what helps us to know what questions to ask.
• 01:30 In fact, many of the business problem solving methodologies
• 01:33 rely on the scientific method of analysis.
• 01:37 This provides a logical approach for organizing our problem solving process.
• 01:42 The scientific method is defined as, a method of analysis
• 01:46 that involve systematic observation, measurement, and experimentation.
• 01:50 It includes the formulation, testing, and modification of hypothesis.
• 01:54 As you can see, the process starts by asking a question and
• 01:58 then creating an hypothesis for the answer to that question.
• 02:01 Next develop an experiment to test the hypothesis,
• 02:05 make certain the experiment is valid, and if not develop a new experiment.
• 02:09 Then use the experiment to collect the data and analyze the data.
• 02:12 From the analysis draw a conclusion about the validity of the hypothesis or
• 02:17 go back and create a new hypothesis.
• 02:19 You can see this combines both inductive and deductive reasoning.
• 02:23 Creating the hypothesis is inductive and performing the tests is deductive.
• 02:28 The approach also organizes the problem solving activities
• 02:31 by giving us a plan of action.
• 02:33 We know what to do next and the methodology is a proven and
• 02:36 well established approach.
• 02:38 So it gives us confidence that it will lead to a solution.
• 02:42 Let's dig a little deeper into the concept of questions and hypothesis.
• 02:46 Problem analysis is an inquiry process, a problem is a difficulty and
• 02:51 we need to analyze the problem when we are not certain of
• 02:54 the best way to remove the difficulty.
• 02:56 Once we know what to do,
• 02:57 we no longer need to analyze the problem we just need to do the work to fix it.
• 03:02 So as part of this inquiry process we first need to formulate the question.
• 03:07 Knowing the question helps us to know the goal or purpose of the experiments and
• 03:11 the data analysis.
• 03:13 We don't run the numbers just to practice doing math,
• 03:15 we're trying to answer a specific question.
• 03:18 I've found that using the cause and effect format helps to formulate the question.
• 03:23 And by that I mean, does this question cause this effect?
• 03:28 We can then restate the question into a set of hypothesis.
• 03:31 These hypothesis look at both side of the question.
• 03:35 We call the two perspectives the Null Hypothesis and the Alternative Hypothesis.
• 03:39 The Null hypothesis is always framed in a such a way
• 03:43 as to say that the dependent variable is not affecting the independent variable.
• 03:48 In other words, there's nothing to see here.
• 03:51 And of course, the alternative hypothesis is the opposite.
• 03:54 It states that the dependent variable is affected by the independent variable.
• 03:58 We have an entire course that explains hypothesis testing.
• 04:02 Not just the right of the hypothesis, but how to prove or
• 04:05 disprove the hypothesis with statistical data.
• 04:08 But let me give you a quick overview.
• 04:10 Statistical hypothesis testing allows us to test a claim or hypothesis
• 04:15 about a characteristic in a data set and determine its statistical validity.
• 04:20 Based upon the hypothesis test, we can accept or reject this claim.
• 04:25 And while we do this with a sample of data, we can draw our conclusions about
• 04:29 the entire population that the sample represents.
• 04:31 With that analysis we can answer questions posed by our analyses and
• 04:36 determine if there is really a difference between this and that.
• 04:40 Knowing what the difference makers are will normally lead us to the cause or
• 04:44 source of the problem.
• 04:46 Now we normally used hypothesis testing to confirm our suspicions
• 04:51 not as a tool to discover new information.
• 04:53 And that is why we need to apply our judgement and
• 04:55 experience to a situation to create a question of hypothesis.
• 05:00 When doing a Six Sigma hypothesis testing analysis,
• 05:03 I recommend that you intentionally create several hypotheses.
• 05:07 And then use the data that was already collected
• 05:10 in the Measure phase to test these hypotheses.
• 05:13 Don't worry,
• 05:13 in the hypothesis testing course we will discuss the various analysis.
• 05:17 If you already have your data set,
• 05:19 each hypothesis test will only take a few minutes to statistically analyze the data.
• 05:25 And that is what makes this approach so
• 05:27 powerful, the data tells us what is relevant.
• 05:30 It's not based upon a lucky guess or
• 05:32 a forceful PowerPoint presentation, rather the data tells us what is happening.
• 05:37 And leads us to the cause or causes of the problem.
• 05:42 In this Analyze stage we wanna discover the underlying cause so
• 05:46 that we fix the correct thing once we get to the Improve stage.
• 05:49 The scientific method is a proven problem solving approach
• 05:54 that will lead us through this stage.

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