Home / Statistical Tools / Control Charts / Control Chart Wizard
Control Chart Wizard¶
The Control Chart Wizard asks a short series of questions about your data and then opens one of seven chart types for you.
From Excel click...
QXL Stat Tools > Control Charts > Control Chart Wizard, the first entry on that menu.
The wizard builds the older kind of chart
A chart created through the wizard is produced by the previous chart engine, not the one behind the ribbon's own chart entries. It looks similar and the arithmetic is the same, but it does not get the Control Chart task pane, and it carries a different set of after-the-fact controls. If you already know which chart you want, launching it from its own entry on the Control Charts menu gives you the current version. The differences are set out below.
What It Asks¶
The wizard has four question screens, but any one run reaches only two or three of them: continuous data takes two questions, count data takes three. Each path then ends on a confirmation screen naming the chart it has chosen.
- Is the data continuous or count data? Continuous data is measured on a scale and can carry decimals. Count data arrives as whole numbers.
- What is the subgroup size? Four answers: N=1, Between 2 and 10, More than 10, and Variable subgroup size. This is the step that picks between the variable charts: N=1 gives I-MR, Between 2 and 10 gives Xbar-R, and both More than 10 and Variable subgroup size give Xbar-S.
- One defect per unit, or more than one? Whether an item is judged pass or fail as a whole, or can carry several defects at once.
- Is the sample size constant? Whether every sample covers the same number of units.
Your answers select the chart. Cancel at any point and nothing is created.
What It Can Produce¶
Seven chart types, out of the twenty-one the Control Charts menu offers:
| From the wizard | Also on the menu directly |
|---|---|
| Xbar-R | Xbar-R and Xbar-S |
| Xbar-S | Xbar-R and Xbar-S |
| I-MR | I-MR |
| p | p Chart |
| np | np Chart |
| c | c Chart |
| u | u Chart |
The wizard cannot reach the other fourteen. I-MR-R/S, Levey-Jennings, Z-MR, EWMA, CUSUM, Laney P', Laney U', G, T, and the single-panel Xbar, R, S, Individuals and Moving Range variants are all launched from their own entries only.
How a Wizard Chart Differs¶
| From the ribbon's chart entry | From the wizard | |
|---|---|---|
| After-the-fact controls | The Control Chart task pane | Slider and check box controls drawn on the worksheet |
| Choosing how many points are shown | Start at and Size in the pane, with ◀ Page and Page ▶ | Two sliders on the sheet, labelled Start at and Number of points to display, the second of which always shows the total count beside it |
| Turning zone lines and markers on and off | Show zone lines, Show out-of-control indicators and Show outlier markers in the pane | The 'Show OOC' and 'Show Zone Lines' check boxes on the sheet |
| Most points that can be displayed at once | No fixed limit | 10,000 |
| Points shown when the chart is first drawn | The last 1,000, or all of them if there are fewer | The last 1,000, or all of them if there are fewer |
| Needs Quantum XL loaded to change the view | Yes, the pane is part of the add-in | No, the on-sheet controls are ordinary Excel controls |
That last row is the one real advantage the older charts keep: their sliders and check boxes go on working for somebody who opens the workbook without Quantum XL installed.
Everything else about the chart is decided in the dialog the wizard opens. That dialog belongs to the previous chart engine and is not the dialog documented on the chart pages linked above. Its settings, including which out-of-control tests run and how the limits are estimated, differ from the current one. Launch the chart from its own entry on the Control Charts menu to get the dialog those pages describe.
See Also¶
- Control Charts: every chart the ribbon offers
- Create Control Charts: the Data Selection window and how to lay out your data
- Data Sources: what each family of chart reads
- Update Control Charts