By the analyze phase, you and your team should have the project well defined, smart goals and objectives identified, the scope of your project narrowed, a project metric established, and pertinent data collected. You’re now ready to determine which of the x’s is causing the variation in your product, process, or service. Hopefully, the team has spent considerable time at Gemba observing the current condition and asking questions of those that work there every day. Everything acquired to this point must be assimilated into the team’s thought process, which is very much like putting the pieces of a puzzle together.
Some of the tools you’ll need to help you start to put the puzzle together are the following:
- Process map, swim lane diagram, spaghetti diagram, or current state value stream map are tools you can use to understand the overall picture and what’s going on. They require the team to go to Gemba, observe, and ask questions. Especially look at areas where hand-offs occur from one functional area to another. It is vital to ensure all input and output criteria are maintained as the process flows from one step to another.
- Your data collection and measurement process must be adequate to ensure you have useful information to conduct a thorough analysis. Specifically, you should have stratified your data to help you determine which of the 6Ms is affecting your process. Stratification by Man, Machine, Material, Method, Mother Nature, or Measurement will give you clues that will help you identify the source of variation to concentrate on further. A simple tool to stratify data is a check sheet.
- I find using histograms, box plots, and other graphical analysis tools for variable data useful in helping me see the shape of my data and looking at the mean, median, standard deviation, and other descriptive statistics. All these tools help in seeing what’s going on.
- Control charts are helpful because they indicate whether your process is in statistical control and if the observed variation is due to common cause or assignable cause variation.
The goal of the analyze phase is to identify root causes and confirm them with the data you collect. The deliverable is to develop a theory for the root cause of the problem and to test and ensure it is correct.
During the analyze phase tollgate review you and your team should be prepared to answer the following questions posed by your project sponsor or champion:
- How did you identify the potential causes of variation in your process? What tools did you use to identify the variation? Can you show me the data you collected?
- Which factors turned out to be the root causes and contributed the most to the variation?
- How did you verify the root causes? Can you show me your charts and graphs?
- Did you uncover any quick hit improvements?