IS0514 Lecture - Week 2 Best Practice Development Methodology

Slide 2 IS0514 – Semester 2 Week 2 Today's Lecture What is considered as best practice Information System Development What is part of best practice? What processes are required? How should the processes be put together?

Slide 3 IS0514 – Semester 2 Week 2 SDLC and Approaches Software Development Life Cycle (SDLC) Planning Why build the system? Analysis Who, what, when, where will the system be? Design How will the system work? Implementation System delivery Approaches Structured Development Rapid Application Development Agile Development

Slide 4 IS0514 – Semester 2 Week 2 What is best practice? Model Visually Use case driven Architecture centric Iterative and Incremental Grady Booch, Ivar Jacobson and James Rumbaugh (1999) The Unified Modelling Language User Guide

Slide 5 IS0514 – Semester 2 Week 2 Model Visually Picture speaks a thousand words Choice of language Traditional approach ERD / DFD / etc Object Oriented Approach UML <= in this module Choice of approach As sketch As blue print Fowler (2005) UML Distilled

Slide 6 IS0514 – Semester 2 Week 2 Use-Case Driven Use Case is a single interaction between user and system What the client wants the system to do Link to clients Constant reminder of client Unit from which later models are derived Thread that links through development Functional / non-functional / usability requirements?

Slide 7 IS0514 – Semester 2 Week 2 Use Case Driven – why? Build only what the client wants Don’t build technically driven project Everyone focused upon same requirements Developers Clients Users

Slide 8 IS0514 – Semester 2 Week 2 Architecture Centric - History ApproachWhen MainframeUp to late 1980s Thick clientLate 1980s – mid 1990s Web / Thin clientMid 1990s - present Web servicesLast few years

Slide 9 IS0514 – Semester 2 Week 2 Architecture Centric Many ways to solve problems Find best solution to provide value from choices available Architecture significantly affects everything else Very important to DESIGN This year focus is ANALYSIS

Slide 10 IS0514 – Semester 2 Week 2 Iterative Development The lifecycle is cyclic: Analyse a bit Design that bit Code the design Test the code Refine the analysis and repeat

Slide 11 IS0514 – Semester 2 Week 2 Iterative & Incremental Delivery

Slide 12 IS0514 – Semester 2 Week 2 How does this help? Mini-Projects Promotes early risk mitigation People think best short term Plan, design & code a little Encourages participation Allowing for correction sooner Allows software to evolve Exposes problems earlier Management of Risk

Slide 13 IS0514 – Semester 2 Week 2 Activity 1 – are diagrams enough? Do you think diagrams are enough? In groups of 3-4 spend 5 minutes discussing this. At the end of the time please be ready to share your discussions with the rest of the class.

Slide 14 IS0514 – Semester 2 Week 2 Activity 1 - Answer

Slide 15 IS0514 – Semester 2 Week 2 Unified Process Workflows 9 Workflows in 2 types: Engineering Workflows Business Modelling Requirements Analysis and Design Implementation Test Deployment Supporting Workflows Project Management Environment Configuration and change management

Slide 16 IS0514 – Semester 2 Week 2 Iterative Approach for the Full Lifecycle Phases Process Workflows Iterations Supporting Workflows Management Environment Business Modeling Implementation Test Analysis & Design Preliminary Iteration(s) Iter. #1 Iter. #2 Iter. #n Iter. #n+1 Iter. #n+2 Iter. #m Iter. #m+1 Deployment Configuration Mgmt Requirements ElaborationTransitionInceptionConstruction Workflows group activities logically In an iteration, you walk through all workflows

Slide 17 IS0514 – Semester 2 Week 2 Each major workflow describes how to create and maintain a particular model Models and Workflows Design Model Implementation Model Test Model realized by implemented by Requirements Workflow Analysis Design Workflow Implementation Workflow Test Workflow Use-Case Model Business Modeling Business Model verified by Core process workflows Iterative process resulting in a series of models which work with each other

Slide 18 IS0514 – Semester 2 Week 2 USDP Phases Inception Phase Business Case Technical Feasibility – Can We build it? Economic Feasibility – Is it worth building? Organisation Feasibility – If we build it will it be used? Elaboration Phase Enough System Analysis and Design to build system Construction Phase Build and Test Transition Phase Deploy

Slide 19 IS0514 – Semester 2 Week 2 Activity 2 – Do all projects need all the workflows? Do you think all projects need all the workflows? In groups of 3-4 spend 5 minutes discussing this. At the end of the time please be ready to share your discussions with the rest of the class.

Slide 20 IS0514 – Semester 2 Week 2 Activity 2 – Answer

Slide 21 IS0514 – Semester 2 Week 2 Summary How do you develop software? What is part of best practice? What processes are required? How should the processes be put together? Next week: Use Cases

Slide 22 IS0514 – Semester 2 Week 2 This weeks reading ESSENTIAL READING Dennis A, Wixom B, and Tegarden D (2005) System Analysis and Design with UML version 2 second edition, Wiley Pages Further reading Bennett, S., McRobb, S. and Farmer, R. (2002) Object- Oriented Systems Analysis and Design using UML, 2nd Edition, McGraw-Hill Chapter 3