Example: bench balance
The same technician measures the same 500.000 g check mass five times at the start of each working day, removing and replacing it between readings. The study covers 30 days and contains 150 readings.
Download the bench balance example (CSV)This is the same example used in Help. subgroup_id identifies the day, D01–D30, and measured_mass_g contains the readings in grams. date records the day; reference_g records the fixed check-mass value entered on Inputs.
1. Create the analysis
In the sidebar, open Measurement systems, choose Stability, and name the analysis. Select New blank worksheet and Create analysis.
2. Import the data
On Worksheet, choose Import. Select the downloaded file or paste its contents. Set the delimiter to Comma, use Decimal dot, and check First row contains column names. Preview the import, then choose Import into worksheet. Keep every row in its original order.
3. Assign the input columns
On Inputs, choose By period label in Subgrouping method. Assign subgroup_id to Period / subgroup ID and measured_mass_g to Measurements, selecting each from the column picker. Each day contains five readings. Keep the days in collection order.
4. Set the study options
Enter 500.000 in Reference value (optional). This adds the check-mass reference to the mean chart.
Open Control chart rules. Leave all five optional rules checked: 7-point trend, 6 on one side, 14 alternating, 2 of 3 beyond 2σ and 4 of 5 beyond 1σ. Beyond-limit checks always apply.
5. Run analysis
Choose Run analysis, then open Results.
6. Interpret results
Understand each point
Each point represents five readings of the same check mass on one day. Read the charts from left to right, in collection order. Periods 1–30 correspond to D01–D30.
Check the range first
The range is the gap between the highest and lowest reading that day. No range points are flagged. The average range is 0.008367 g and the upper limit is 0.01769 g. This checks within-day spread.
Daily range in grams: the gap between the highest and lowest of five check-mass readings. View full-size chart (opens in a new tab) Check the average
Each mean-chart point is the average of five readings. D05, D07, D13 and D17 are below the lower limit. D26–D30 are above the upper limit. The later days have higher average readings. The 500.000 g reference line is not a control limit.
Daily average in grams for the same 500.000 g check mass. Periods 1–30 correspond to D01–D30. View full-size chart (opens in a new tab) Read the highlighted points
D02 has mean about 500.002 g, inside the limits 499.9979–500.0076 g, but is flagged as part of a six-on-one-side pattern. A point can participate in a multi-point signal without crossing a limit. There are 72 rule entries across 30 flagged mean points and no flagged range points; several entries can concern one day.
Decide what to investigate
The daily average changes while the range has no flagged points. Check balance, check-mass and environmental records for the flagged days. The limits use the whole sequence, including the late increase; investigate before adopting a baseline. These are measurement-system checks, not product specifications.
More details: read each result section
Complete result tables use six significant digits, as in Help.
Stability summary
The study contains 30 daily subgroups of five repeated readings of the same check mass. There are 72 rule entries across 30 flagged mean points and no flagged range points. Several rules can flag one point, including in-limit pattern points, so this is not 72 independent events.
| Statistic | Value |
|---|---|
| Subgroups (k) | 30 |
| Subgroup size (n) | 5 |
| Grand mean (X̄̄) | 500.003 |
| Average range (R̄) | 0.00836667 |
| Within-subgroup σ | 0.00359702 |
| Signals | 72 |
| Reference | 500 |
| Mean − reference | 0.00275333 |
Control limits and mean-chart zones
Limits were estimated from the whole sequence, including the late increase. They describe the current analysis and should not be adopted as an established stable baseline without investigation. These are measurement-system checks, not product fill-weight specifications.
| Statistic | Value |
|---|---|
| X̄ lower control limit | 499.998 |
| X̄ upper control limit | 500.008 |
| R lower control limit | 0 |
| R upper control limit | 0.0176871 |
| X̄ −1σ | 500.001 |
| X̄ +1σ | 500.004 |
| X̄ −2σ | 500 |
| X̄ +2σ | 500.006 |
Period means, ranges and signals
All 30 periods retain their mean, range and signal labels. Compare flagged periods with their daily records; several rules may identify the same period.
| Period | Mean (X̄) | Range (R) | Mean signals | Range signals |
|---|---|---|---|---|
| 1 | 499.999 | 0.009 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side | None |
| 2 | 500.002 | 0.014 | 6 on one side | None |
| 3 | 499.999 | 0.014 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side | None |
| 4 | 500 | 0.003 | 4 of 5 beyond 1σ, 6 on one side | None |
| 5 | 499.998 | 0.008 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 6 | 500.001 | 0.016 | 4 of 5 beyond 1σ, 6 on one side | None |
| 7 | 499.996 | 0.013 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 8 | 500.001 | 0.008 | 4 of 5 beyond 1σ, 6 on one side | None |
| 9 | 500.001 | 0.007 | 4 of 5 beyond 1σ, 6 on one side | None |
| 10 | 499.999 | 0.003 | 4 of 5 beyond 1σ, 6 on one side | None |
| 11 | 500 | 0.008 | 4 of 5 beyond 1σ, 6 on one side | None |
| 12 | 500 | 0.011 | 4 of 5 beyond 1σ, 6 on one side | None |
| 13 | 499.997 | 0.007 | 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 14 | 500.001 | 0.012 | 4 of 5 beyond 1σ, 6 on one side | None |
| 15 | 500 | 0.004 | 4 of 5 beyond 1σ, 6 on one side | None |
| 16 | 499.999 | 0.004 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side | None |
| 17 | 499.997 | 0.005 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 18 | 500.001 | 0.01 | 6 on one side | None |
| 19 | 500.002 | 0.009 | 6 on one side | None |
| 20 | 500.001 | 0.007 | 6 on one side | None |
| 21 | 500.001 | 0.005 | 6 on one side | None |
| 22 | 500.005 | 0.014 | 6 on one side | None |
| 23 | 500.004 | 0.009 | 6 on one side | None |
| 24 | 500.005 | 0.007 | 4 of 5 beyond 1σ, 6 on one side | None |
| 25 | 500.004 | 0.006 | 6 on one side | None |
| 26 | 500.011 | 0.006 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 27 | 500.015 | 0.007 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 28 | 500.017 | 0.008 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 29 | 500.015 | 0.009 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
| 30 | 500.013 | 0.008 | 2 of 3 beyond 2σ, 4 of 5 beyond 1σ, 6 on one side, beyond limits | None |
Control chart signal details
Each row identifies one returned chart index and rule. Multiple rows can concern the same point; use the charts to locate the affected daily subgroup.
| Index (as returned) | Chart | Rule |
|---|---|---|
| 1 | X̄ | 2 of 3 beyond 2σ |
| 1 | X̄ | 4 of 5 beyond 1σ |
| 1 | X̄ | 6 on one side |
| 10 | X̄ | 4 of 5 beyond 1σ |
| 10 | X̄ | 6 on one side |
| 11 | X̄ | 4 of 5 beyond 1σ |
| 11 | X̄ | 6 on one side |
| 12 | X̄ | 4 of 5 beyond 1σ |
| 12 | X̄ | 6 on one side |
| 13 | X̄ | 4 of 5 beyond 1σ |
| 13 | X̄ | 6 on one side |
| 13 | X̄ | beyond limits |
| 14 | X̄ | 4 of 5 beyond 1σ |
| 14 | X̄ | 6 on one side |
| 15 | X̄ | 4 of 5 beyond 1σ |
| 15 | X̄ | 6 on one side |
| 16 | X̄ | 2 of 3 beyond 2σ |
| 16 | X̄ | 4 of 5 beyond 1σ |
| 16 | X̄ | 6 on one side |
| 17 | X̄ | 2 of 3 beyond 2σ |
| 17 | X̄ | 4 of 5 beyond 1σ |
| 17 | X̄ | 6 on one side |
| 17 | X̄ | beyond limits |
| 18 | X̄ | 6 on one side |
| 19 | X̄ | 6 on one side |
| 2 | X̄ | 6 on one side |
| 20 | X̄ | 6 on one side |
| 21 | X̄ | 6 on one side |
| 22 | X̄ | 6 on one side |
| 23 | X̄ | 6 on one side |
| 24 | X̄ | 4 of 5 beyond 1σ |
| 24 | X̄ | 6 on one side |
| 25 | X̄ | 6 on one side |
| 26 | X̄ | 2 of 3 beyond 2σ |
| 26 | X̄ | 4 of 5 beyond 1σ |
| 26 | X̄ | 6 on one side |
| 26 | X̄ | beyond limits |
| 27 | X̄ | 2 of 3 beyond 2σ |
| 27 | X̄ | 4 of 5 beyond 1σ |
| 27 | X̄ | 6 on one side |
| 27 | X̄ | beyond limits |
| 28 | X̄ | 2 of 3 beyond 2σ |
| 28 | X̄ | 4 of 5 beyond 1σ |
| 28 | X̄ | 6 on one side |
| 28 | X̄ | beyond limits |
| 29 | X̄ | 2 of 3 beyond 2σ |
| 29 | X̄ | 4 of 5 beyond 1σ |
| 29 | X̄ | 6 on one side |
| 29 | X̄ | beyond limits |
| 3 | X̄ | 2 of 3 beyond 2σ |
| 3 | X̄ | 4 of 5 beyond 1σ |
| 3 | X̄ | 6 on one side |
| 30 | X̄ | 2 of 3 beyond 2σ |
| 30 | X̄ | 4 of 5 beyond 1σ |
| 30 | X̄ | 6 on one side |
| 30 | X̄ | beyond limits |
| 4 | X̄ | 4 of 5 beyond 1σ |
| 4 | X̄ | 6 on one side |
| 5 | X̄ | 2 of 3 beyond 2σ |
| 5 | X̄ | 4 of 5 beyond 1σ |
| 5 | X̄ | 6 on one side |
| 5 | X̄ | beyond limits |
| 6 | X̄ | 4 of 5 beyond 1σ |
| 6 | X̄ | 6 on one side |
| 7 | X̄ | 2 of 3 beyond 2σ |
| 7 | X̄ | 4 of 5 beyond 1σ |
| 7 | X̄ | 6 on one side |
| 7 | X̄ | beyond limits |
| 8 | X̄ | 4 of 5 beyond 1σ |
| 8 | X̄ | 6 on one side |
| 9 | X̄ | 4 of 5 beyond 1σ |
| 9 | X̄ | 6 on one side |
7. Create a report
Keep both Stability charts, Stability summary, Control limits and mean-chart zones, Period means, ranges and signals and Control chart signal details. Record the check mass, daily sampling routine and investigated dates. The calculated limits include the late increase.
Choose Add to report from the completed run. Open Choose individual items and advanced options to select tables and charts, then choose Add to draft. Hidden items stay in the saved analysis.
Name the report and add the purpose of the study and your interpretation. Choose Save, review Preview, then use Export → Download HTML. The example below contains the full selected content, including results beyond one screen.