Partial scenarios describe parts or extracts of complete scenarios or processes. They show only interesting, difficult, risky or important aspects of some greater process.

Concentrating on these essentials brings several benefits:

• You avoid trivial parts of scenarios
• You work more economically by leaving out unnecessary, non-important or low-priority aspects. That saves time/effort in creating and maintaining documentation!
• Smaller scenarios might be easier to understand (if (!) you make very clear which parts of the overall scenario you left out!)

A risk of partial scenarios might be consumers that don’t understand the prerequisites or preconditions of a partial scenario. Use annotations within your diagrams to explicitly clarify such required knowledge or facts.

In the figure shown below, you find a complete scenario first, and a nice partial scenario as an extract afterwards.

As you see, the first interactions seem quite trivial. Therefore, we can simple leave them out in a partial scenario: