<h3 dir="auto">Description</h3>
<p dir="auto">When viewing the DAG history in Tree View, individual DAG run times are available by hovering over the DAG run. As an Airflow user, I would like the average execution time to be readily available in the UI -&gt; DAG -&gt; Tree View.<br>
It can be an average over the last <em>n</em> runs, <em>n</em> being the number of runs selected in the Tree View.</p>
<h3 dir="auto">Use case/motivation</h3>
<p dir="auto">The average DAG run execution information can help our team make decisions such as the optimal schedule interval for a DAG.</p>
<h3 dir="auto">Related issues</h3>
<p dir="auto"><em>No response</em></p>
<h3 dir="auto">Are you willing to submit a PR?</h3>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> Yes I am willing to submit a PR!</li>
</ul>
<h3 dir="auto">Code of Conduct</h3>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I agree to follow this project's <a href="https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md">Code of Conduct</a></li>
</ul>
<p dir="auto">It would be useful to show a running average dag run duration in the grid view. This could be a plotted line on top of the duration bar chart.</p>
<p dir="auto">The average duration should be calculated on the webserver and included  with a dag run's info.</p>
<p dir="auto">Bonus: We could possibly use the average duration to calculate a very rough "Expected time to completion" for active dag runs.</p>