What is a Pick chart and how is it used in Six Sigma?
A Pick chart is a tool used that can be used in any process evaluations when trying to pre-process raw data.It is a method used to narrow down a large quantity of raw data to get to the root problems.It is often used in the pre-processing stages of Six Sigma after data collection.
There are many useful ways for processing data.One of these is to focus on a sample and distilling the data for particular purposes.This is very valuable in the early stages of processing when the volume of raw material is great and you need to glean out the most useful information.
The process begins as you assess the customer feedback.You need to break down the data into context and needs.This is often called pre-processing as you analyze the customer responses and extract key phrases to determine what exactly their needs are and in what context those needs exist.Keep a good record of these conversations and highlight in different colors the needs and context in their responses to ensure a traceable link to the original source.This will aide greatly in preparing the data for further distillation.
After pre-processing however, there is often too much data to easily distill.In these cases, it may be necessary to cut down the data even further while maintaining an appropriate representative sample.This can save time and energy in the long run.
A Pick chart is appropriate to use at this stage if pre-processing has resulted in more than a hundred remaining data groups.The steps you should follow to create a Pick chart are:
1. On an empty wall chart, post the theme question that the team is trying to answer along the top. This provides an important focal point for deciding what's most useful.You will want to continually ask yourself this same question to ensure your samples are relevant to the problem at hand.
2. Place each element of the data set on a separate note, like post-its or cards with thumb tacks.Arranging the notes on the empty chart towards the left-hand side.
3. Team members will then read each note, considering whether or not that element should remain as part of the critical sample.These notes will moved and arranged on the right hand side of the chart.
At this point, the data is distilled to the point that it can be taken and processed for particular purposes using tools like Affinity Diagrams, Net-Touch, or KJ Analysis.
In an affinity diagram, everyone's self-stick notes are posted on a wall and each is read by enough members of the team to begin the grouping process.
In Net-Touch, everyone holds onto their own notes and watches the facilitator for cues to offer a note for grouping. A practical use for this process is during the building of an interview discussion guide. The process includes the following steps:
1. Everyone in the group writes open-ended questions that address the VOC learning objectives
2. People hold onto their own notes.
3. A facilitator takes one note from the group, at random.
4. Reading that note they ask, "Does anyone have a question that belongs with this one?"
5. Because everyone is familiar with his/her own notes, this provides efficiency.
6. The facilitator collects all the notes that are offered, forming a cluster with the original seed note.
7. Repeat steps 3-6 until all the notes have found their way into a cluster.
8. Now the team can work together to subdivide large clusters into smaller groups and title them.
Lastly is a KJ analysis.There are many kinds of KJ analysis, each distinguished by the theme question posed in its upper left corner.A commonality is that all KJs seek facts that answer the theme question, so you won't typically see this method used for brainstorming.