# Analyze SPC Data with Check Details

You've now seen all three ways to look at quality data:

| Screen | Shows | Use it for |
|---|---|---|
| Check Table | One check at a time | Reviewing or correcting a specific check |
| Check Summary | Counts of checks by status | Were checks done on time? |
| Check Details | Item values across many checks | Trends, statistics and SPC |

:::action[Review the coating data]

1. Navigate to **Quality → Analysis → Check Details**.
2. Select `Coating SPC Checks` and today's date range, then get the data. Each row is one five-minute check.
3. Turn on **Statistics** and **Show Item Spec** and review the min, max, average, standard deviation and calculated control limits.
4. Use the menu to switch between row and column views, and export the data.
5. Notice highlighted cells. They mark possible SPC rule violations, even where the value is within spec.

:::

:::action[Apply SPC rules]

1. Select a `Coating Thickness` value and open the trend view.
2. Choose the `Nelson` rule set and apply it.
3. Click the violation markers to see which rules fired, and compare the points with the mean, 1σ, 2σ and control limit lines.
4. Look at the **Histogram** tab. Check whether the values are centered, how widely they spread, and whether there are outliers or a skew.

:::

The simulated coating tags drift slowly up and down, so you should see trend rules fire even though every value is acceptable. That's exactly what SPC is for: spotting drift before it becomes a failure.

::embed-section{src="../../../kanoa-quality/checkDetails.md#applying-spc-rules" collapsed="true" summary="Reference Materials: Applying SPC Rules"}

::embed-section{src="../../../kanoa-quality/checkDetails.md#statistical-process-control-overview" collapsed="true" summary="Reference Materials: Statistical Process Control Overview"}

:::tip
Run Check Details for `Machining - First Article Inspection` too, with **Show Production Info** turned on. FAI data is a few inspections per run, tied to the item's spec; coating data is a steady stream of samples for monitoring the process.
:::