Software Life Cycle Models PDF

Chapter 10 Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Chapter 10 Systems Analysis and Design in a Changing World 6th Ed...

Chapter 10 Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Chapter 10 Systems Analysis and Design in a Changing World 6th Ed Satzinger, Jackson & Burd Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  The System Development Life Cycle Methodologies, Models, Tools, and Techniques Agile Development The Unified Process, Extreme Programming, and Scrum Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Compare the underlying assumptions and uses of a predictive and an adaptive system development life cycle (SDLC) Explain what makes up a system development methodology—the SDLC as well as models, tools, and techniques Describe the key features of Agile development Understand and describe the key features of the Unified Process, Extreme Programming, and Scrum Agile system development methodologies Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Chapter 1 demonstrated a system development project that used an iterative and agile system development life cycle (SDLC) Later chapters focused on Systems Analysis activities and tasks and some System Design activities and tasks Now we return to look at the SDLC and related concepts in more detail Predictive versus Adaptive SDLC variations Activities and Tasks of System Support Models, Methodologies, Tools and Techniques Agile Development Specific SDLC Approaches Unified Process (UP) Extreme Programming (XP) Scrum Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  There are two general approaches to the SDLC Predictive Approach to the SDLC Waterfall model Assumes the project can be planned in advance and that the information system can be developed according to the plan Requirements are well understood and/or low technical risk Adaptive Approach to the SDLC Iterative model (as see in this text) Assumes the project must be more flexible and adapt to changing needs as the project progresses Requirements and needs are uncertain and/or high technical risk Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Most projects fall on a continuum between Predictive and Adaptive Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Earlier approach based on engineering Typically have sequential Phases Phases are related groups of development activities, such as planning, analysis, design, implementation, and deployment Waterfall model SDLC that assumes phases can be completed sequentially with no overlap or iteration Once one phase is completed, you fall over the waterfall to the next phase, no going back Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved. Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved. Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  More flexibility, but still assumes predictive planning and sequential phases Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Emerged in response to increasingly complex requirements and uncertain technological environments Always includes iterations where some of design and implementation is done from the beginning Many developers claim it is the only way to develop information systems Many IS managers are still sceptical due to apparent lack of overall plan Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Incremental development Completes portions of the system in small increments and integrated as the project progresses Sometimes considered “growing” a system Walking Skeleton The complete system structure is built first, but with bare-bones functionality Advantage of both=> it gets to the user sooner so business can begin Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Six Core Processes go across iterations Multiple Iterations as required Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Methodologies help in the following: Provides guidelines for every facet of system development: What to do when, why and how Specifies an SDLC with activities and tasks Specifies project planning and project management models and reporting Specifies analysis and design models to create Specifies implementation and testing techniques Specifies deployment and support techniques Other term used is System Development Process Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  A Methodology includes a collection of techniques that are used to complete activities and tasks, including modeling, for every aspect of the project Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Model An abstraction of an important aspect of the real world. Makes it possible to understand a complex concept by focusing only on a relevant part Each model shows a different aspect of the concept Crucial for communicating project information In IS, some models are of system components that will be developed Other models are used to manage the development process Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved. Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Tools Software applications that assists developers in creating models or other components required for a project Integrated Development Environment (IDE) set of tools that work together to provide a comprehensive development environment Visual Modeling Tools Tools to create graphical models Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Some typical tools Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Technique A collection of guidelines that help an analyst complete an activity or task Learning techniques is the key to having expertise in a field Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  A guiding philosophy and set of guidelines for developing information systems in an unknown, rapidly changing environment Chaordic A term for adaptive projects – chaotic yet ordered Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Agile Values in “Manifesto for Agile Software Development” Value responding to change over following a plan Value individuals and interactions over processes and tools Value working software over comprehensive documentation Value customer collaboration over contract negotiation Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Agile Modeling (AM) – 12 Principles A philosophy – build only necessary models that are useful and at the right level of detail Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Develop software as the primary goal Don’t get distracted by documentation or models Enable the next effort as your secondary goal Be aware of next step versions or revisions Minimize your modeling activity Only build what helps move the project forward Embrace change and change incrementally Take small steps that keep you on-track and that can be reversed if necessary Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Model with a purpose Model to understand Model to communicate Build multiple models Look at problems from different perspectives Build high-quality models and get feedback Focus on content rather than representation Informal hand-drawn models are sometimes okay Always focus on stakeholder needs Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Learn from each other with open communication Know your models and how to use them Adapt to specific project needs Maximize stakeholder ROI Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  The UP was the early leader in adaptive approaches UP and UML (Unified Modeling Language) were developed together Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  UP Phases organize iterations into four primary areas of focus during a project Inception phase – getting the project started Elaboration – understanding the system requirements Construction – building the system Transitions – preparing for and moving to deploying the new system Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  UP SDLC divides iterations into four phases Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Objectives of each phase Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  UP SDLC divides iterations into four phases Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  A set of functionally related development activities Each discipline are all the activities related to achieving one objective in the development project Two types of disciplines Development disciplines Management – planning and control disciplines Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Development Disciplines Business modeling Requirements Design Implementation Testing Deployment Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Planning and Control disciplines Configuration and change management Project management Environment Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Disciplines are used across all iterations Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved. Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Takes the best practices of software development and extends them “to the extreme” Focus intensely on proven industry practices Combine them in unique ways to get better results XP Core Values Communication Simplicity Feedback Courage Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  XP Practices Planning – based on user stories Testing – thorough testing at every step Pair Programming – watch, inspect, trade off Simple Designs – Agile modeling principles Refactoring – redo and cleanup as you go Owning the code collectively – egoless development, anyone can review and improve code Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  XP Practices (cont) Continuous integration – grow the software continuously On-site customer – get sign-off as you go System metaphor – what should the final system look like (major components) Small releases – turn over to user frequently Forty-hour work week – don’t overload the developers Coding standards – follow standards for code Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved. Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Three level approach (three rings) Outside ring – create user stories and define acceptance tests Middle ring – conduct tests and do overall planning Inside ring – iterations of coding and testing Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved. Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Combination of principles of Rugby and Agile Intense effort involving the entire team for a defined period of time Product backlog Prioritized list of user requirements Product owner The client stakeholder who controls backlog Scrum master Scrum project manager Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Scrum sprint A time-controlled mini-project to implement part of the system Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  Scope of each sprint is frozen (but can be reduced if necessary) Time period is kept constant Daily Scrum meeting What have you done since the last daily Scrum (during the last 24 hours)? What will you do by the next daily Scrum? What kept you or is keeping you from completing your work? Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  This chapter covers approaches to system development in more detail There are two approaches to the SDLC: Predictive and Adaptive A predictive SDLC, also known as the waterfall model, is used when it is possible to plan the project completely in advance An Adaptive SDLC, which uses iteration, is used when the requirements are less certain and the project will need to react to changes Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.  All new System development project use a methodology (or development process) and many are available. A methodology includes an SDLC and tools, techniques, and models Agile development is the current trend in system development Unified Process is a formal iterative approach which uses UML models (with Agile philosophy) and UP disciplines Extreme Programming (XP) is an iterative approach which takes good practices to the extreme Scrum is an iterative approach using a Scrum Sprint Systems Analysis and Design in a Changing World, 7th edition - Chapter 10 ©2016. Cengage Learning. All rights reserved.