Analysis & Design

• Draw.io
  https://app.diagrams.net/

  A free online diagramming software alternative to Microsoft Visio for building UML, E-R, and network diagrams, as well as process and organizational charts.

• Entity-Relationship (ER) Diagram Tutorial
  https://www.lucidchart.com/pages/er-diagrams?er=1

  Tutorial that describes how to create an entity-relationship (ER) diagram to design a database. Describes the components of an ER diagram, as well as the symbols for different notation schemes. Provides a full example in crow's feet notation.

• Entity-Relationship Diagrams (Visual Paradigm)
  https://www.visual-paradigm.com/guide/data-modeling/what-is-entity-relationship-diagram/

  Tutorial on entity-relationship (ER) diagrams using crow's foot notation to design a relational database schema. Walks through the entire design process - from listing entities in the Requirements stage to building the logical and physical models.

• System Use Cases: an Agile Introduction
  http://agilemodeling.com/artifacts/systemUseCase.htm

  Discusses and presents both informal and formal system uses cases used in agile projects.

• UML 2 Class Diagrams: an Agile Introduction
  http://www.agilemodeling.com/artifacts/classDiagram.htm

  Presents the first few iterations of a class diagram for a university enrollment system. Good example that not only uses simple, standard UML syntax, but also discusses the importance of developing diagrams iteratively.