Creating streams

Teams usually create streams to work on a new release of a system, work on a variant, and work on a patch. You can create a stream from a baseline or another stream. You can also select multiple streams and baselines at one time and create a stream for each one.

Before you begin

To create global streams from streams or from baselines, and to modify stream attributes and links, you must have the corresponding permission.
By default, the Configuration Lead and Administrator roles are assigned these privileges.

Note: To control who can replace contributions or add, remove, and move contributions in streams, administrators can set finer-grained permissions. For details, see "Configuration Lead" in Role-based permissions for Global Configuration Management.
To create local streams (from local baselines), you must have permission to create streams in the corresponding application.

Important: Creating a global stream directly from another stream does not create a baseline. If you need baselines of the stream selections to capture a frozen set of artifacts for auditing or regulatory purposes, create a baseline and then create a stream from that baseline.

Note: When a topic states that a global configuration is at the root, the root refers to the visible global configuration in the tree view. The root might be a member of another global configuration, so root does not necessarily mean the top-most global configuration.

About this task

Recall that a stream is modifiable while a baseline is frozen.

Teams use streams to accomplish goals like these:

Your team needs you to create streams for a new product or system. You must first create a component, which automatically creates an initial baseline and then creates an initial stream from the baseline. See Creating a component to establish a work context.
Your team needs to create a variant. You can create a variant from either a stream or a baseline. See Creating a variant by branching.
Your team needs to create a patch for an earlier version of part of your product or system hierarchy. You find the baseline that contains the local configurations to be fixed, and you create a stream from that baseline.
Your team wants to experiment and try out changes in a different stream. In this case, you might create a stream directly from another stream instead of from a baseline. When you create the stream "in place", the new stream replaces the existing stream. When the team finishes trying out changes, you can replace the new stream with the one you used before. See the example later in this topic.

Procedure

Find the configuration to create the stream from. You can also select multiple configurations at one time.

You can search for a configuration by using Quick Search.
Right-click a configuration in the tree view and select Create Stream. If you chose multiple configurations in step 1, right-click one of your choices.
The placement of the selected configuration in the tree view determines what is included and how it is included in the created stream.

You can't create a stream from a local stream. If you selected a local stream in step 1, the Create Stream menu option isn't shown.
- Created from a baseline that is the root of the hierarchy: Creates a stream with the same members as the selected configuration. The new stream will be displayed in the tree view as the root.
  For example, you want to create a stabilization stream so that you can make select changes to it before creating the release milestone baseline.
  
  Note: If the root is a baseline, you can't create streams from its nested baselines. To create a stream from a nested baseline, right-click the nested baseline and click Show as Root. Then, right-click the new root and click Create Stream.
- Created from a baseline nested in a stream hierarchy: Creates a stream with the same members as the selected configuration. If created as a new tree, the new stream will be displayed in the tree view as the root; that is, the new stream will not be in the context of the baseline hierarchy.
  For example, you want to use just the new stream elsewhere.
- Created from a baseline where the root of the hierarchy is a stream: Creates the stream hierarchy from one or multiple selected baselines (global and local configurations). Baselines above the selections that are required to complete the stream hierarchy are replaced with new streams automatically.
  For example, the selected baseline is called Battery. The Battery baseline is under Case-back, which is a global configuration baseline under Phone, a global configuration stream. When you create a stream, the selected Battery baseline is created as a stream, but so is the Case-back global configuration above Battery, because it is a required part of the stream hierarchy.
  
  For example, your team needs to create a variant during ongoing development work.
- Created from at least one baseline with a root baseline staging stream: Replaces one or multiple selected baselines (global and local configurations) with new streams. Global configuration baselines are replaced with new baseline staging streams. Baselines above the selections that are required to complete the stream hierarchy are replaced with new streams automatically.
  For example, your team needs to create a patch that contain only the configurations that you need to fix.
- Created in place from a stream: Creates a stream that replaces the selection. Nested configurations are preserved. As noted in the Before you begin section, if you must capture the frozen set of artifacts for regulatory purposes, take a baseline first, and then create a stream from the baseline.
  For example, your team needs a temporary stream for experiments or to new develop new capabilities. Typically, you keep the new stream in place temporarily, and replace it with the original selection later.
- Created in place from a baseline: Creates a stream that replaces the baseline.
  For example, your team is ready to begin work on a new release of a component.
- Created in a new tree from a stream: Creates a branch from a stream that's currently under development.
  For example, your team needs a stream to experiment or develop new capabilities in parallel without changing other components. Suppose your team is working on the Adaptive Cruise Control component of an Automobile platform. A question arises whether the Luxury Automobile needs a more sophisticated variation of this component. To explore this question in a separate stream, click Create Stream on the Adaptive Cruise Control stream, which is nested in the Automobile hierarchy; then, choose New Tree because you want to work in a new stream (which you name Adaptive Cruise Control 2.0) without changing the Automobile or Luxury Automobile components. If your organization decides to adopt the new Adaptive Cruise Control 2.0 feature, you can replace the Adaptive Cruise Control stream in the Luxury Automobile component with the Adaptive Cruise Control 2.0 stream.
Enter a name suffix. The name suffix is used to form new stream names by appending it to the component name of each configuration.
If prompted, choose where to create the new stream.
- In Place: The new stream replaces the corresponding selection in the hierarchy and is assigned the same branch value as the tree root. When you select multiple configurations, this is the only option shown.
- New Tree: The new stream becomes the root of a new hierarchy and is assigned the same branch value as the stream it's created from. When you select the tree root, this is the only option shown.
Add tags or a branch value, as needed.

After the stream is created, you can modify tag and custom attribute values, add or remove tag and custom attribute values, and add or remove links for the stream. Learn about adopting changes made to attribute and link labels or values after they were added to a global configuration in Tags, attribute values, and links.
Create the stream.

Starting in version 6.0.1, you can create a stream in the Global Configuration Management application for a configuration contributed by a different IBM® Engineering Lifecycle Management application, if you have permission to create streams in the contributing applications. IBM Engineering Workflow Management streams must be created manually in that application, and then you can replace the baselines with the streams. For other contributing Engineering Lifecycle Management applications, if the stream cannot be created, fix the problem and then create the stream again. Only the streams that failed are created after you fix the problem.