Unified Modelling Language (UML)

Introduction

As the strategic value or requirement of software increases for many companies, the industry looks for techniques to automate the production of software, to improve quality and reduce cost and time-to-market. Businesses seek techniques to manage the complexity of systems as they increase in scope and scale. The Unified Modelling Language (UML) was designed to respond to these needs. In this paper we will discuss why we use a UML, as well as a few types of UML's such as Class Diagrams, Use Case Diagrams, and Activity Diagrams.

In the early 80's and 90's many different methodologies and models were being used for designing software programs, business systems, and database development. A standard was necessary. Booch, Rumbaugh, and Jacobson championed the cause of creating a standardized method for software modelling. In 1997, Booch, Rumbaugh, and Jacobson's Unified Modelling Language was accepted as the defacto standard. Industry leaders like Microsoft, Oracle, IBM, and HP accepted UML as the standard.

What is a UML?

UML is defined by its founders; Booch, Rumbaugh, Jacobson (1998), as a standard "modelling language for writing software blueprints." (p. 136) Modelling is important whether you are building a house, designing a software program, defining an enterprise infrastructure or designing a database. The development process of any project must be followed to ensure the scope of a project is laid out, the needs of the users and reason for the project are documented and understood, programmer's or developers need to be clear about their tasks, the end product needs documentation, testing and an implementation plan. I am describing the System Life Cycle Development Model. UML is a graphical based tool that allows for deliverables in all stages of the model. A model allows all the stakeholders involved to Visualize, Specify, Construct, and Document the project all from one set of plans or blueprints.

To organize program code more efficiently, programmers often create "objects" that are sets of structured data within programs. Using UML, developers and architects can make a blueprint of a project; much like ERD diagrams are used for relational design. The relationships created in the diagram dictate how the database is built. Then Use Case diagrams are used to determine user interaction. (i.e. User clicks on button, action X is invoked, output Y occurs.) The Use Case Model describes the proposed functionality of the new system. From this simple diagram the requirements of the ordering system can be ...