Understand Local and External Decisions

Local decisions have to be modeled from scratch and are created and activated in the context of process applications. External decisions are ready to be used, already modeled decisions that are created and activated in decision applications. They can be called and used across multiple process applications as well as in other external applications.

Here's a comparison of local and external decisions.

Local decision	External decision
Created as a component of a process application.	Created as a component of a decision application.
Can be used only in the context of the process application in which it is created. Local decisions support simple use cases.	Gives more flexibility to designers as external decisions can be used in multiple process applications and also can be called by external applications. External decisions support complex use cases.
Only one decision can be created per process application.	More than one decisions can be used per process application.
Decision services of a local decision become active only when the process application is activated. The REST API endpoints of the exposed decision services are not readily active. They become active only when the process application is activated.	As only activated decision applications and their versions are available as external decisions, so decision services of external decisions are always active. The REST API endpoints of the exposed decision services are already active and can be readily called from other process applications and external clients.
Versions aren't supported	Versions are supported. If multiple versions exist for a particular decision application, you can only use one version per process application. If required, you can change to a higher or lower version but cannot use more than one version of the same decision application in a process application.

Some external decisions may have badges to indicate their status.

• New version available: There is a new version available for the current decision.

  Under the Versions section of the external decision details window, the current and new versions are listed. If you want to use the new version, click the Use button. You’ll be prompted to confirm. On confirmation, the decision gets updated to the new version.

  You’ll get a warning if the new version that you are trying to use is incompatible and hence can cause validation errors. You can choose to cancel the update or update anyway and fix the errors later.

• Update model: The linked decision application (current version) has been updated and activated.

  Click and open the external decision details window. Under the Versions section, the currently used decision is listed with a Update button. Click Update and then confirm when prompted to update to the latest version.

• Missing decision: The linked decision application has been deactivated or deleted.

  As a workaround, you can delete the decision and use an available active decision application.