SCCM 1711 Tech Preview is now released! See https://docs.microsoft.com/en-us/sccm/core/get-started/technical-preview & https://docs.microsoft.com/en-us/sccm/core/get-started/capabilities-in-technical-preview-1711 for the documentation

We’ve made a lot of improvements to Nested Task Sequence. Previous Tech Previews limited the scenarios with content references to PXE/Boot Media, the policy generation has been updated to resolve all and now all scenarios can be used (Client/PXE/Media)

Console actions are fixed in many instances where we didn’t traverse the referenced packages/content
Export now exports child task sequence and referenced content – secrets are cleared from the referenced task sequences too
Task Sequence import now works and detects duplicates
Copy action copies parent and all reference to child task sequences
Delete action detects if there’s a parent child relationship and displays what’s affected
Similarly deleting packages that are in child task sequences is detected and shown in the delete package wizard
Initially we had limited to one level – now there’s no limit, but use that wisely
Related to the above, we do not permit a circular reference i.e. a parent cannot reference same parent, a parent cannot reference a child that references same parent – we traverse the entire chain
Create Prestage Content is updated to work for task sequences with multiple child references
Deployment Verification now detects when the child contains the ‘high-impact’ steps
Standalone media creation detects and adds all task sequence and content references and completes end-to-end

Things to note
We do not permit selecting a task sequence with a Boot Image reference, for any deployment that requires a boot image that reference has to be on the parent
Any chain containing a disabled task sequence will fail – the continue on error won’t work for that step
Criteria for popping the ‘high-impact’ warning are not detected in Software Center when the child contains the ‘high-impact’ steps, in this case our recommendation is to use the Task Sequence User Notification properties to force the ‘high-impact’ warning
If a child task sequence has a package reference removed the parent does not detect this. To workaround, make any edit to the parent (anything that activates Apply)

As always we appreciate any and all feedback, try it out and let us know what you think

Hi. This feature was turned back on for 1710 Tech Preview

The limitations are still the same, there are some changes in the back end that you won’t be able to see for now. Currently a task sequence with any package references in child steps won’t resolve content when run in the full OS – we’ve a ton of work to do with policy to solve that. Good news is that the scenario will work when launched from WinPE (PXE/Media). Also, nesting will work in the full OS for any steps that don’t require content e.g. Run Command Line, Set Task Sequence Variable (variables are global to all steps!), Connect to UNC etc.
Import/Export doesn’t traverse all child task sequences
We block selecting the parent task sequence for one level only
Some actions like Distribute Content won’t see all references, same with the view

As always we appreciate any and all feedback

Updating status to started. The ability to call another task sequence from a task sequence is added in 1704 Tech Preview – see here https://docs.microsoft.com/en-us/sccm/core/get-started/capabilities-in-technical-preview-1704 for more details

Please note this is an early release and there’s some limitations. We wanted to show you all our work in progress and gather some feedback such as nesting depth.
Currently a task sequence with any package references in child steps won’t resolve content when run in the full OS – we’ve a ton of work to do with policy to solve that. Good news is that the scenario will work when launched from WinPE (PXE/Media). Also, nesting will work in the full OS for any steps that don’t require content e.g. Run Command Line, Set Task Sequence Variable (variables are global to all steps!), Connect to UNC etc.
Import/Export doesn’t traverse all child task sequences
We block selecting the parent task sequence for one level only
Some actions like Distribute Content won’t see all references, same with the view

We’re really excited about this feature and appreciate any and all feedback

David (our Director of Engineering) shared this last night…
https://twitter.com/djammmer/status/854486013720248320

This item is now planned for future release – we’ll update later which Tech Preview this feature will be available in.

RE: Ben – we have an open Doc. item for clarifying non-OSD task sequence use. I’ve added your comments to that item – thanks for passing them on

RE: David Stein – agreed – that’s something we want to avoid. After prototyping one of the first things we did was list all potential issues like this and create a test case for each – 50+ from that exercise and growing.