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

# Redline a run

> Modify a procedure mid-run when reality diverges from the plan, adding steps, editing fields, and documenting deviations without losing traceability or breaking parallel batched runs.

A redline is an in-flight modification to a procedure made during a specific run: split a step, add a field measurement, correct an instruction, add a missing step, or build a procedure as you fly. It lives on the run rather than the procedure template, so it edits the build with full traceability and can be reconciled back into the template later. For where redlines sit among the other run concepts, see the [Overview](/build-hardware/runs-and-execution/overview).

<Note>
  You must have a role with the `createRedline` and `updateRedline` permissions to redline a run.
</Note>

## When to use a redline versus an issue

These two are easy to confuse:

| Use a **redline** when…                                                                                            | Use an **[issue](/track-quality/issues)** when…                                |
| ------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------ |
| The procedure needs to change for this run, such as adding a step, modifying a field, or correcting an instruction | The part has a problem, such as a nonconformance, defect, or supplier issue    |
| The change is procedural: what work happens, in what order                                                         | The change is dispositional: what to do with the affected inventory            |
| You want to update the procedure template afterward                                                                | You want to disposition the affected unit, such as use as is, rework, or scrap |

Redlines and issues often go together: an issue might trigger a redline when a step missed something and you need to add a verification step. Both are recorded, both have reviewers, and both contribute to the build's history.

## Redline versus procedure revision

Redlines are for this build; procedure revisions are for the future. If the same change keeps recurring across runs, escalate to engineering and revise the procedure rather than redlining each run individually. A redline that should apply to every future build is really a procedure revision.

## Deviations

A **deviation** is an accepted out-of-range measurement: the team acknowledges a value fell outside its tolerance and records the rationale. The in-step mechanic for capturing an out-of-range value is covered in [Execute a run step](/build-hardware/runs-and-execution/step-execution).

## Start a redline

There are two entry points:

* Click the three-dots indicator on the step's action bar to redline an existing step.
* Use the redlines button in the run header to select a position where a new step can be added. If you don't select a position, the step is added to the end of the run.

When adding a new step through a redline, you can link it directly to an issue. The issue persists when you click **Save and Add Another Step**, letting you create a series of redlines related to an issue in quick succession. Use the search and filters to narrow results and find the exact step you want to add. For example, you can pull steps from a standard rework procedure in rapid succession to create many redlined steps that then get approved all at once.

If you don't select a step from the results menu, a new step is created with the selected step type. This lets you build entire runs from scratch without a procedure, in a build-as-you-fly manner, then save them back to a procedure later through the merge process.

## Edit a step in redline

Steps in redline are indicated with a warning at the top of the step and a red pencil icon on the step queue. While a step is in redline, you can edit, add, duplicate, or remove its content, fields, datagrid rows and columns, and values.

* Redline steps cannot be completed or failed.
* Canceling a redline at any time returns the step to its previous actionable condition.
* Dependencies attached to a redline step can be deleted. Both steps must be in redline to add a dependency between them.

## Redline a standard step

Redlining a standard step works the same way. Click the ellipsis next to the step title and click **Redline Step**.

## Approve redlines

Add reviewers through the multi-select user dropdown on the **Review Redlines** page, then assign them to the appropriate redlines.

If you've been assigned as a reviewer, run steps in redline show up in the run header and can be viewed and approved in the **Review Redlines** popup. The **Review Center** in the top right, next to your avatar, shows all redlines waiting on your approval.

Each redline in **Review Redlines** and the **Review Center** gives you a live diff of the changes. Click **Expand Diff** to see them. After reviewing, you can approve them, reject them, or add feedback for the original editor to act on.

* When assigned to review multiple redlines, you can approve an individual redline on a run step or approve all redlines assigned to you on a single run at once, from the bottom of the **Review Redlines** page. This is built for sequences of connected redlines that should be reviewed together.
* The **Submit** button on the step approves and submits in one click whenever you're permitted to approve. If you can approve the redline yourself, the button assigns you as the reviewer, records your approval, and submits the redline together, and its tooltip reads **Approve & submit**. If the redline is already approved, the button just submits, and the tooltip reads **Submit**. When a reviewer's approval is still required, the button is disabled with a **Pending reviewer approval** tooltip. To always submit redlines automatically, enable [auto-submit redlines](/administration/quality-settings/enable-auto-submit-redlines) in settings.
* If you've been assigned as a reviewer for merged redlines, you can approve all the run steps with merged redlines at once from the **Review Center**. This helps when a redline has been merged to many other runs.

The **History and Merge** page shows all completed redlines and the complete history of changes and feedback for each step.

<Note>
  The number of approvers required and the roles allowed to review are configurable. See [set the redline approver count](/administration/production-settings/set-redline-approver-count), [configure procedure reviewer roles](/administration/production-settings/configure-procedure-reviewer-roles), and [configure standard step reviewer roles](/administration/production-settings/configure-standard-step-reviewer-roles).
</Note>

## Merge redlines

A redline improvement made on one run can be duplicated into other similar runs and into procedures. If 20 other runs use the same instructions, merging brings them all up to date in one push. Run steps and procedure steps you merge to automatically update to be identical to the source step when the merge is accepted.

A redline must be submitted before it can be merged, from the redline **History and Merge** page. You have two merge targets:

* **Merge to a procedure**: merge to an existing step or to a new step at the end of the procedure. If the procedure is not in a draft state, ION automatically creates a new draft version to merge into.
* **Merge to run(s)**: select many runs and steps to merge to. Before merging, assign a reviewer so they can approve all the merges at once instead of approving each merged redline independently. Once the merge completes, each destination run step is placed in redline and mirrors the source step. As with any redline, you still have to approve and submit them, so assign the reviewer before merging.

## Related

* [Run and run step states](/build-hardware/runs-and-execution/overview#states)
* [Execute a run step](/build-hardware/runs-and-execution/step-execution)
* [Manage run batches](/build-hardware/runs-and-execution/run-batches)
* [Procedures](/build-hardware/procedures)
* [Issues](/track-quality/issues)