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annie_zangi

Staff

Joined:

May 27, 2014

Control Charts are easy in JMP 10

 

JMP 10 introduces a snazzy way to create control charts with a new platform called Control Chart Builder. JMP's prior Control Charts were designed over two decades ago for the classic process engineer in manufacturing and were past due for an overhaul.

The more we listened to which customers were running control charts and how they were using them, the more I was surprised to learn that people from nearly any field, including health care, medicine, sales, banking, scientific fields and education were running control charts. This was when we realized JMP needed something easily accessible to everyone.

The new Control Chart Builder platform in JMP 10 works much like Graph Builder with a drag-and-drop interface. It displays an Individual and Moving Range chart the instant you drag over a Y, and switches to an XBar and R chart when you drag over a subgroup column.

To replicate the chart below in JMP:

  • Open Cars Sold.jmp, which you can download from the JMP File Exchange on the JMP website
  • From the Analyze menu, choose Quality and Process->Control Chart Builder
  • Drag Volume ($M) sold to the Y-axis area of the chart
  •  To see the labels on the X-axis, drag the column Date to the X-axis area of the chart to see date labels on the X-axis
  • Since sales managers are on alert for low-volume months and always looking to repeat high-volume months, the limits on Control Charts can be useful in sifting out the noise from the more interesting events.

    The car sales volume data in this example comes from the U.S. Census Bureau, Economic Indicators.

    In the plot above, we first notice the drastic drop in volume for June and July 1998, caused in part by the General Motors labor strike. In 2008, we see the deep continued drop in sales resulting from the 2008 recession. The blue reference line is set at December, 2007, which the US National Bureau of Economic Research states was the beginning of the late 2000’s recession.

    To see just the top (Individuals) chart, simply click on the axis label for Moving Range and drag the label out.

    We hope you will find Control Charts are more fun to drive now.

    8 Comments
    WP_Comment
    Community Member

    Ryan Ong wrote:

    Will JMP 10's Control Chart Builder have a way to switch to Levey Jennings or other types of control charts?

    WP_Comment
    Community Member

    Annie Dudley Zangi wrote:

    Yes! The Control Chart Builder turns the control chart inside out, letting you set the statistics used for the points and limits separately, which makes the control charts more flexible. To switch to a Levey Jennings chart, you need only change the sigma used to create the limits. To do this, right-click on the graph and choose Limits->Sigma, then Levey Jennings.

    Take a look at both the Points->Statistic and the Limits->Sigma menus and you'll see many other types of control chart choices.

    WP_Comment
    Community Member

    Custom Tests in the Control Chart Builder - JMP Blog wrote:

    [...] my last blog post, I noted that the Control Chart Builder is an overhaul of the older Control Chart platform. One of [...]

    WP_Comment
    Community Member

    Nesting Variables in Control Chart Builder in JMP 10 wrote:

    [...] my first Control Chart Builder blog post â Control Charts are easy in JMP 10,â I used a column named â Dateâ on the X-axis. When I downloaded the data, it didnâ t arrive [...]

    WP_Comment
    Community Member

    Christine Huang wrote:

    How did you get the date on the x-axis? I only see "subgroup" on the x-axis. When I go to put the date on the x-axis for the independent and moving range chart, the graph changes to an Xbar and R chart. I want to maintain an independent and moving range chart with time on the x-axis.

    WP_Comment
    Community Member

    Annie Dudley Zangi wrote:

    Thanks for your question. Youâ re correct that the variable on x-axis acts as a subgroup variable. In this example, all the dates were unique, so the subgroup size was one. The only time it switches from an Individual and Moving Range set to an Xbar and Range set of charts is when the subgroup size is greater than one.

    WP_Comment
    Community Member

    Lisa Hall wrote:

    Is it possible to show a trend line on an SPC chart, similar to what can be added to a line chart in Excel?

    Annie Dudley Zangi wrote:

    Lisa, While neither of the Control Chart platforms in JMP have an option to plot a trend line, you can get the trend line thru Bivariate, then add the line to any graph using the Customize.. option. Here's an example for the Y Function used to plot a regression line on a graph:

    Y Function(131.49624 - 2.3084042*x,x);