Extending functional requirements to subsystems

As functional requirements use text paragraphs to describe a product's purposes, functional models illustrate those purposes with a hierarchy of functional blocks. Decomposition of functional models into finer detail produces parent and child models within a functional architecture. These layers of models describe the functionality of the entire system, from the major subsystems to the lowest-level subsystems.

In Teamcenter, a function object represents a purpose of the system. For each object in a functional model, the following elements can be represented:

• Interfaces (inside and outside the system)
• Inputs and outputs
• Relationships with other functions in the system

Typically, systems engineers use trace links for allocating functions to elements in downstream or upstream structures, such as:

• Other functions in the same structure or in different Function views.
• Requirement specifications, logical models, and physical models in Systems Engineering.

Trace links set up paths in which elements precede and succeed one another across the system's various domains. By tracing these defining and complying relationships, systems engineers can analyze change impact both upstream and downstream.

Tip Trace links can exist also between Systems Engineering objects and subsets in 4th Generation Design. Collaborative designers can analyze these relationships through the Systems Engineering cross-domain tracing feature.

In Systems Engineering, you can build functional structures by:

• Creating the structure in the Function view.
• Creating diagrams in Microsoft Office Visio Professional.
• Importing spreadsheets from Microsoft Excel.

Note A function object has a BodyText property, whose value is rich text content that you define. To convey information about the function, for example, its purpose in the overall architecture, you can:

• Edit the content in the MS Word view.
• Export the content to Microsoft Office Word.