> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dash360.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Understanding Your Data

> The common reasons a Report Studio report shows unexpected numbers: snapshots, views and filters, Work Package and CAM permissions, and caching, plus performance tips and pitfalls.

# Understanding Your Data

If a report shows numbers you do not expect, or two people see different results from the same report, the cause is almost always one of a handful of things. Work through this checklist before assuming there is a bug.

<Note>
  This page is part of the [Report Studio](/user-guide/reporting/report-designer) guide. For formula-specific issues, see the [Calculated Field Cookbook](/user-guide/reporting/report-designer-calculated-fields).
</Note>

## The five usual suspects

<Steps>
  <Step title="Snapshots: are you looking at the right project version?">
    A report runs against one or more **project snapshots** (saved versions of a project's cost data). If the wrong snapshot is selected, or a newer snapshot exists, the numbers will not match what you expect. Confirm which projects and snapshots the report is using.
  </Step>

  <Step title="Filters: is something narrowing the data?">
    Filters reduce what the report shows and they affect totals. Check both:

    * **Report filters** at the top (WBS, Work Package, CAM, Cost Class, Resource Type, and more).
    * **In-grid filters** on grid reports (header filter, filter row, search box).

    A common surprise is the default **Resource Type** filter on charts (Labor, Non-Labor, Travel). If a category is missing, check it.
  </Step>

  <Step title="Permissions: are you allowed to see all the rows?">
    What you see is limited by your **Work Package permissions**. Two users can open the same report and see different rows. This is by design, not a bug. See [Permissions and what each user sees](#permissions-and-what-each-user-sees) below.
  </Step>

  <Step title="Views: is a saved view changing the layout?">
    A saved view changes which columns show, the order, grouping, and sorting. It does not change the data, but it can hide columns or group things in a way that makes totals look different. Switch to the default view to compare.
  </Step>

  <Step title="Caching: could the data be a little stale?">
    Report data is cached for up to **30 minutes**. If a project or your permissions changed very recently, you might see the previous result until the cache refreshes. See [Caching and stale data](#caching-and-stale-data).
  </Step>
</Steps>

## Permissions and what each user sees

For non-administrator users, the report only returns rows the user is permitted to see, based on **Work Package permissions**. There are three levels of grant:

| Grant                     | Effect                                                    |
| ------------------------- | --------------------------------------------------------- |
| **All** (wildcard)        | The user sees every work package in the selected projects |
| **WBS branch**            | The user sees every work package under a given WBS branch |
| **Specific work package** | The user sees only that exact WBS and work package        |

Permissions also have to apply to reporting (the grant must cover the report viewer). **Administrators see everything**, with no permission filter.

<Warning>
  If a colleague sees rows you do not, the difference is usually permissions. Ask an administrator to review your Work Package permissions for the project. After a permissions change, allow a few minutes for cached data to refresh.
</Warning>

## Caching and stale data

To keep reports fast, Dash360 caches results for up to **30 minutes** per combination of projects, fields, and filters.

* Re-running the **same** report with the **same** filters is fast because it uses the cache.
* Changing filters, fields, or projects runs a **fresh** query.
* Cached data is automatically cleared when the underlying **project snapshot** changes or when your **permissions** change, so you do not normally need to do anything.

If you suspect stale data, change a filter and change it back, or wait for the cache window to pass, then re-run.

## Performance: make reports responsive

Grid reports (Data Grid and Pivot Grid) run on the server: the server does the filtering, sorting, grouping, and totals, then sends back only what the screen needs. The biggest lever you control is **how many rows the report has to process**.

<Tip>
  **Filter early, explore later.** Apply project, WBS, Work Package, and Cost Class filters before you sort, group, or expand a large report. A report scoped to one WBS branch responds far faster than the whole project.
</Tip>

More ways to keep reports quick:

* **Select only the projects you need.** Each extra snapshot adds rows.
* **Add only the fields and columns you need.** Fewer columns means less data per row.
* **Expand groups on demand** instead of expanding everything at once on a huge dataset.
* **Lean on the cache.** Repeating the same filtered report is fast; wildly different filters each time are not.
* **Keep cross-tabs sensible.** In a Pivot Grid, avoid putting a very high-cardinality field (like many months across many years) on Columns without a time filter.

## General pitfalls to avoid

<Warning>
  * **Blended Cost Class.** Summing Item Cost without separating Cost Class adds Budget, Actual, and Earned together. Filter Cost Class or split it with calculated fields (see the [Budget vs Actual recipe](/user-guide/reporting/report-designer-fields#recipe-budget-vs-actual)).
  * **Assuming views save filters.** Saved views remember layout (columns, order, grouping, sorting), not filters. Filters reset on reload.
  * **Renaming captions and expecting the data to change.** Captions are display-only.
  * **Too many categories on a chart.** Filter, group small values, or pick a higher WBS level.
  * **Reading an aggregate as if it were summed from rows.** Aggregate calculated fields are recomputed at each group and total, so an average of averages is not the overall average. See the [Calculated Field Cookbook](/user-guide/reporting/report-designer-calculated-fields).
</Warning>

## Still wrong after all that?

If the numbers are still off after checking snapshots, filters, permissions, views, and the cache, and after confirming any calculated fields against the [cookbook](/user-guide/reporting/report-designer-calculated-fields), capture the report name, the selected projects, the filters in effect, and what you expected versus what you saw, then contact your administrator.

## Where to go next

<CardGroup cols={2}>
  <Card title="Report Gallery" href="/user-guide/reporting/reports-viewer">
    Run, filter, save views, and export.
  </Card>

  <Card title="Calculated Field Cookbook" href="/user-guide/reporting/report-designer-calculated-fields">
    Ready-to-use formulas and fixes for wrong results.
  </Card>
</CardGroup>