You customize your semantic model in the non-production environments such as development or test by creating branches and adding steps to those branches.

You use a branch or version to publish your changes to the model. You can apply the model from the branch to a local service instance for testing. When the changes are correct, you can merge that branch with the main branch. You can merge multiple branches with the main branch over time. When you have a set of changes finalized, you can version the main branch and promote that branch to the production environment. After promoting the customizations to the production environment, you can’t directly add further customizations to the semantic model in the production environment.

You can copy the steps from the main branch, edit them directly, and later merge them with the main branch. However, you must ensure not to perform two or multiple levels of copies. For example, you must not copy steps from the main branch to another branch, then copy the steps over to yet another branch, and then merge the second branch with the main branch.

You can customize the model by extending prebuilt dimensions with additional attributes from another data source, by adding a fact to an existing subject area, and by reorganizing the prebuilt subject areas to create a new subject area to name a few. If you've merged an external application, then note that both external semantic model and semantic model extensions can co exist. On the Publish Model page, select "Yes" if you want the external semantic model to be included.

Don’t maintain changes in a local branch for long periods of time. Local branches can become out of synchrony when changes to the Oracle Fusion Data Intelligence environment occur. Use a local branch for development, then merge to the main branch after user acceptance testing. Promote the main branch from Development to Production environments using the Semantic Extensions bundle. Whenever a system extension run is replaying the master branch, you must not edit the main branch during this time as that might cause a conflict leading to failure of the semantic extensions.