Domain Model Domain Model Lecture 3 Lecture 3 Hoa Sen University 1 Agenda Agenda  Recap  Case Requirements  Elaboration process  Domain model – Introduction and definition – How to create a domain model Hoa Sen University 2 Recap Recap  Inception activities  Different types of requirements  Scenario & Use case  Writing Use Cases  Use Case Diagram  Use case relationships Hoa Sen University 3 Case requirements Case requirements  The requirements for the first iteration of the NextGen POS: – Implement a basic, key scenario of the Process Sale use case – Implement a Start Up use case as necessary to support the initialization needs of the iteration – Nothing fancy or complex is handled – No collaboration with external services – No complex pricing rules are applied Hoa Sen University 4 Case requirements Case requirements  Monopoly – Implement a basic, key scenario of the Play Monopoly Game use case: players moving around the squares of the board – Implement a start Up use case as necessary to support the initialization needs of the iteration – Two to eight players can play – A game is played as a series of rounds Hoa Sen University 5 Case requirements Case requirements  Monopoly (cont) – Play the game for only 20 rounds – After the dice are rolled, the name of the player and the roll are displayed. When the player moves and lands on a square, the name of the player and the name of the square that the player landed on are displayed. – In iteration-1 there is no money, no winner or loser, no properties to buy or rent to pay, and no special squares of any kind – Square name will be “Go”, “Square 1”, “Square 2”, …“Square 39” Hoa Sen University 6 Incremental Development Incremental Development  Incremental development for the same use case across iteration Hoa Sen University 7 1 A use case or feature is often too complex to complete in one short iteration. Therefore, different parts or scenarios must be allocated to different iterations. Use Case Process Sale 2 3 . . . Use Case Process Sale Use Case Process Sale Use Case Process Rentals Feature: Logging Process: inception Process: inception  What happened in inception – Last only one week – Most actors, goals and use cases named – Most use cases written in brief format; 10-20% of the use cases are written in fully dressed detail – Recommendations on what components to buy/build/reuse, to be refined in elaboration  Technical proof-of-concept prototypes and other investigations to explore the technical feasibility of special requirements/  High-level candidate architecture and components proposed – NOT necessary to be final or correct  Plan for the first iteration Hoa Sen University 8 Process: on to Elaboration Process: on to Elaboration  What happens in Elaboration – The core, risky software architecture is programmed and tested – The majority of requirements are discovered and stabilized – The major risks are mitigated or retired – Commonly, 2 or more timeboxed iterations  Elaboration in one sentence – Build the core architecture, resolve the high-risk elements, define most requirements, and estimate the overall schedule and resources. Hoa Sen University 9 Process: on to Elaboration Process: on to Elaboration  Best practices in elaboration – Do short timeboxed risk-driven iterations – Start programming early – Adaptively design, implement, and test the core and risky parts of the architecture – Test early, often, realistically – Write most of the use cases and other requirements in detail, through a series of workshops, once per elaboration iteration Hoa Sen University 10