Reference models are very similar normal Stages process, but typically use a different metamodel to define compliance requirements. Typically, a metamodel called TTO-Model for Standards (or similar) is already installed on every server, which is equipped to model Chapters and Requirements.

The only difference between a process and a reference model is the process type that can be set in Management > Settings under Process Kind.

Typically a process has to comply only with a specific section of a reference model. For example, a project management process only needs to comply with the Project Planning, Project Monitoring & Control, and Integrated Project Management process areas of the CMMI-DEV standard. Therefore the reference models are normally broken down into Scopes, which contain a subset of all reference model requirements.

To define the scopes for a new reference model, use Management > Compliance and switch to the Scopes tab. It is only visible if the process kind of the current workspace is set to Reference Model (see above). You can create and delete scopes and add reference model elements to them. To efficiently add or remove multiple elements, use the Add all elements, Add all elements in folders, and Remove all elements actions in the … menu:

Per convention, each reference model should have a Default scope, which contains all reference model required that are typically mapped to.

Reference models can also be mapped onto other reference models. For example, it may make sense to map evidence tables in the appendices of some standards onto the standard requirements themselves and then trace your processes only onto the evidence tables. The Compliance Traceability report can then use the cross-reference-model-mappings to show compliance to the original standard without having to map to it directly.

The standard version management for reference models is not supported, so reference models can only have one version.

If you need to version reference models, the models need to be copied to different workspaces, e.g. “Automotive SPICE 3.1” and “Automotive SPICE 4.0”.

When reference models are imported into Stages 7.8 or later, the automatically created version “V0” should be deleted and the working version should be marked valid.