Use Cases Deliver Requirements - Game Developing

The use case in UML is the conveyor of requirements, and it is requirements gathering that is the cornerstone of technical design. The use case is a standardized method of documenting a scenario or an interaction between the user and the software in short, a use. An interaction could be to withdraw money from an ATM or to send the document to the printer or to cause the player character to jump, pick up an object, or swing a sword. A collection of shapes and notations featuring stick figure actors, ellipsoid uses, and line relationships comprise the visual components of a use case diagram.

The simplest use case diagram

Collections of interactions may be plotted together in the same diagram to help organize and prepare for the formal design process. Use case diagrams cannot get too complicated. They are designed to allow the software developer to quickly write down an interaction between the user and the software with a verb-like label, wrap an ellipse around the label, and draw some relationship lines.

For those of you who are curious, formal UML includes varying types of line shapes to describe different types of relationships:

1. Association—the basic relationship representing the communication path between an actor and a use case, drawn as a simple line.
2. Extends—the insertion of additional behavior into a base use case that does not know about it, drawn as a dashed line with an arrowhead with the tag <<extends>> accompanying the line.
3. Generalization—a relationship between a general use case and a more specific use case that inherits and adds features to it, drawn as a solid line with a triangular arrowhead.
4. Inclusion—the insertion of additional behavior into a base use case that explicitly describes the insertion, drawn as a dashed line with an arrowhead with the tag <<include>> accompanying the line.

A use case diagram featuring the automatic teller machine

A use case diagram featuring various relationships