May 15, 2009

Spend 5 minutes understanding 4 UML diagrams before it’s too late!

Posted in Project Management tagged at 2:08 pm by Molly

UML – Unified Modelling Language

Why? To communicate and understand at the same level. Why? To avoid misconceptions!


– capture static relationships of software;
– capture the physical structure of a system;
– understand what classes reference other classes;
– understand which class ‘owns’ another class;
– a CLASS represents a group that has common states and behaviours
– the RELATIONSHIPS include: dependencies, associations, aggregations, compositions, generalisations, associated classes and associated qualifiers.

class diagram example

class diagram example


– capture and define functional requirements;
– a user story and a use case describe ONE THING ONLY that the software needs to do.

use-case example

use-case example


– the “how” does something to something else;
– derived from workflows and flowcharts, because they look very similar;
– defines the behaviour of the model being described.

activity diagram example

activity diagram example


– defines object interaction at runtime to bring software functionality to life in an executed order/sequence;
– used for dynamic modelling.

sequence diagram example

sequence diagram example

USE-CASE NARRATIVES (non-diagram, text only)

– used to describe the use-case in more narrative terms;
– contains: use case name, iteration, summary, pre-conditions, triggers, course of events; alternate paths; post-condition; business rules; notes; author & date.



  1. Nachi said,

    Thanks for the simple Explanations.

    Would you please post a bigger images for the samples?

    Also is there a practical guide on how to create these diagrams? I should learn to use google better i guess then asking around.


  2. asela nuwn said,

    I am BIT Student these bit help to me
    thank you

  3. trimurthy said,

    helllo sir it is nice.can you provide more info

  4. sri said,


  5. Goutham said,

    I took a 5 minute deep dive into UML and now interested in more classic examples, the way you have defined.

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