1. Metamaxim Ltd. Ashley McNeile Metamaxim Ltd. University of Leicester June 2005

2. © 2005 Metamaxim Ltd Metamaxim Metamaxim Ltd. Founded by Ashley McNeile and Nick Simons in 2001 Specialises in using behavioural modelling for exploring system requirements Uses ideas that derive from Jackson System Development (JSD) and Hoare’s Communicating Sequential Processes (CSP) Developed ModelScope -- an executable modelling tool for requirements validation

3. © 2005 Metamaxim Ltd Metamaxim Our Vision Executable Model + GUI Prototypes Real Build (Perhaps generate from the Model) Initial Modelling (Whiteboard) From here on, you are validating working software!

4. © 2005 Metamaxim Ltd Metamaxim Our Focus Executable Model + GUI Prototypes Real Build (Perhaps generate from the Model) Initial Modelling (Whiteboard) From here on, you are validating working software!

5. © 2005 Metamaxim Ltd Metamaxim “Model Driven Agility” Executable Model + GUI Prototypes Real Build (Perhaps generate from the Model) Initial Modelling (Whiteboard) From here on, you are validating working software! High level of abstraction (Events and State Machines) Refactoring is fast Low level of abstraction (Messages and Methods) Refactoring is slower and more difficult

6. © 2005 Metamaxim Ltd Metamaxim Modelling Technique Behaviour Modelling is Crucial Static Models are good for generating Infrastructure code Infrastructure is not important when validating behaviour The user is interested in the behaviour of the application, not the structure of the software We use State Transition Diagrams To show the “business protocol” of objects

7. © 2005 Metamaxim Ltd Metamaxim “Protocol Machine” A software machine that is: Event Driven Quiescent between Events Has a defined “repertoire” of Events When presented with an Event will do one of: Consume it Refuse it (and signal refusal) Ignore it Protocol Machines can be composed The result of composition is another Protocol Machine The composition is the same as || in CSP

8. © 2005 Metamaxim Ltd Metamaxim Order Processing Model Place (an Order) CUSTOMER Register Registered PRODUCT Introduce Discontinue Dropped Available Place Confirm Deliver Invoice ORDER OpenConfirmed Place (an Order) Change Price Cancelled Cancel Change Quantity DeliveredInvoiced Paid Receive Payment

9. © 2005 Metamaxim Ltd Metamaxim Extreme Modelling Tight-loop model, test, demonstrate, change Refactoring to improve the quality of the abstractions The Model A UI that a User can understand and use The business logic A persistency mechanism

10. © 2005 Metamaxim Ltd Metamaxim User Interface

11. © 2005 Metamaxim Ltd Metamaxim On-Going Work “Deontic” modelling Using “typed” protocol machines to qualify possible events in terms of whether they are allowed and/or desired Modelling Workflow and Choreography Investigating how applications (workflows) that expose deontic protocol interfaces can interact