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Chapter 6. Systems Development: Phases, Tools, and Techniques. STUDENT LEARNING OUTCOMES. Define the traditional systems development life cycle (SDLC) and describe the 7 major phases within it. Compare and contrast the various component-based development methodologies.
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Chapter 6 Systems Development: Phases, Tools, and Techniques
STUDENT LEARNING OUTCOMES • Define the traditional systems development life cycle (SDLC) and describe the 7 major phases within it. • Compare and contrast the various component-based development methodologies. • Describe the selfsourcing process as an alternative to the traditional SDLC.
STUDENT LEARNING OUTCOMES • Discuss the importance of prototyping and prototyping within any systems development methodology • Describe the outsourcing environment and how outsourcing works.
CAMERAS USE FILM? • The preceding slide – Kodak 35mm film sales dropped from $7 billion in 2004 to an estimated $1.9 billion in 2010 • Many retailers no longer process 35mm film • Web sites like SnapFish, Photo Bucket, and Flickr are now the norm
CAMERAS USE FILM? • Do you own a 35mm camera? Last time you had 35mm film processed? • Will smartphones spell the end of digital cameras? • Do you know someone who owns a 35mm camera? What do they use it for?
INTRODUCTION • Information systems are the support structure for meeting the company’s strategies and goals • New systems are created because employees request them • New systems are created to obtain a competitive advantage
INTRODUCTION • When developing a new system, you have 3 “who” choices… • Insourcing – IT specialists inside your organization • Selfsourcing – do-it-yourself approach many end users take with little or no help from IT specialists • Outsourcing – a third-party organization (i.e., let someone do the work and pay them for it)
CHAPTER ORGANIZATION • Insourcing and the SDLC • Learning outcome #1 • Component-Based Development • Learning outcome #2 • Selfsourcing • Learning outcome #3 • Prototyping • Learning outcome #4 • Outsourcing • Learning outcome #5
INSOURCING AND THE SDLC • Systems development life cycle (SDLC) - a structured step-by-step approach for developing information systems • 7 distinct phases • Also called a waterfall methodology, an approach in which each phase of the SDLC is followed by another, from planning through implementation
Phase 1: Planning • Planning phase - create a solid plan for developing your information system • Three primary planning activities: • Define the system to be developed • You can’t build every system, so you make choices based on your organization’s priorities, which may be expressed as critical success factors • Critical success factor (CSF) - a factor simply critical to your organization’s success
Phase 1: Planning • Set the project scope • Project scope - clearly defines the high-level system requirements • Scope creep - occurs when the scope of the project increases • Feature creep - occurs when developers add extra features that were not part of the initial requirements • Project scope document - a written definition of the project scope and is usually no longer than a paragraph
Phase 1: Planning • Develop the project plan including tasks, resources, and timeframes • Project plan - defines the what, when, and who questions of system development • Project manager - an individual who is an expert in project planning and management, defines and develops the project plan and tracks the plan to ensure all key project milestones are completed on time • Project milestones - represent key dates for which you need a certain group of activities performed
Phase 1: Planning Sample Project Plan
Phase 2: Analysis • Analysis phase - involves end users and IT specialists working together to gather, understand, and document the business requirements for the proposed system
Phase 2: Analysis • Two primary analysis activities: • Gather the business requirements • Business requirements - the detailed set of knowledge worker requests that the system must meet in order to be successful • Business requirements address the “why” and “what” of your development activities • Joint application development (JAD) - knowledge workers and IT specialists meet, sometimes for several days, to define or review the business requirements for the system
Phase 2: Analysis • Prioritize the requirements • Requirements definition document – prioritizes the business requirements and places them in a formal comprehensive document • Again, you probably can’t do everything, so prioritizing is important • Users sign off on this document which clearly sets the scope for the project
Phase 2: Analysis Take time during analysis to get the business requirements correct. If you find errors, fix them immediately. The cost to fix an error in the early stages of the SDLC is relatively small. In later stages, the cost is huge.
Phase 3: Design • Design phase - build a technical blueprint of how the proposed system will work • Two primary design activities: • Design the technical architecture • Technical architecture - defines the hardware, software, and telecommunications equipment required to run the system
Phase 3: Design • Design system models • This includes GUI screens that users will interface with, database designs (see XLM/C), report formats, software steps, etc • Starting with design, you take on less of an active participation role and act more as a “quality control” function, ensuring that the IT people are designing a system to meet your needs
Phase 4: Development • Development phase - take all of your detailed design documents from the design phase and transform them into an actual system • Two primary development activities: • Build the technical architecture • Build the database and programs • Both of these activities are mostly performed by IT specialists
Phase 5: Testing • Testing phase - verifies that the system works and meets all of the business requirements defined in the analysis phase • Two primary testing activities: • Write the test conditions • Test conditions - the detailed steps the system must perform along with the expected results of each step
Phase 5: Testing • Perform the testing of the system • Unit testing – tests individual units of code • System testing – verifies that the units of code function correctly when integrated • Integration testing – verifies that separate systems work together • User acceptance testing (UAT) – determines if the system satisfies the business requirements
Phase 6: Implementation • Implementation phase - distribute the system to all of the knowledge workers and they begin using the system to perform their everyday jobs • Two primary implementation activities • Write detailed user documentation • User documentation - highlights how to use the system
Phase 6: Implementation • Provide training for the system users • Online training - runs over the Internet or off a CD-ROM • Workshop training - is held in a classroom environment and lead by an instructor
Phase 6: Implementation • Choose the right implementation method • Parallel implementation – use both the old and new system simultaneously • Plunge implementation – discard the old system completely and use the new • Pilot implementation – start with small groups of people on the new system and gradually add more users • Phased implementation – implement the new system in phases
Phase 7: Maintenance • Maintenance phase - monitor and support the new system to ensure it continues to meet the business goals • Two primary maintenance activities: • Build a help desk to support the system users • Help desk - a group of people who responds to knowledge workers’ questions • Provide an environment to support system changes
COMPONENT-BASED DEVELOPMENT • The SDLC focuses only on the project at hand • Component-based development (CBD) – focuses on building small self-contained blocks of code (components) that can be reused across a variety of applications • Using already-developed components • Building new components as needed
Component-Based Development Methodologies • Rapid application development (RAD) • Extreme programming (XP) • Agile methodology
Rapid Application Development (RAD) • Rapid application development (RAD) (also called rapid prototyping) - emphasizes extensive user involvement in the rapid and evolutionary construction of working prototypes of a system to accelerate systems development • Prototypes are models of software • The development team continually designs, develops, and tests the component prototypes until they are finished
Rapid Application Development (RAD) Use already-existing software components Build new software components
Extreme Programming (XP) • Extreme programming (XP) - breaks a project into tiny phases and developers cannot continue on to the next phase until the first phase is complete
Agile Methodology • Agile methodology - a form of XP, aims for customer satisfaction through early and continuous delivery of useful software components
SoA – An Architecture Perspective • Service-oriented architecture (SoA) – perspective that focuses on the development, use, and reuse of small self-contained blocks of code (called services) to meet all application software needs • All CBD methodologies adhere to an SoA • Services are the same as components, which are the same as small self-contained blocks of code
SELFSOURCING • Selfsourcing (end-user development) – the development and support of IT systems by end users with little or no help from IT specialists • Do-it-yourself systems development approach • Can relieve IT specialists of the burden of developing many smaller systems
Selfsourcing Approach • Is similar to traditional SDLC • Big exception is that design, development, testing, and implementation are replaced by the process of prototyping • Prototyping is the process of building models, and – in this case – continually refining those models until they become the final system
Selfsourcing Advantages • Improves requirements determination • Increases end user participation and sense of ownership • Increases speed of development • Reduces invisible backlog • Invisible backlog – list of all systems that an organization needs to develop but never get funded because of the lack of organizational resources
Selfsourcing Disadvantages • Inadequate end user expertise leads to inadequately developed systems • Lack of organizational focus creates “privatized” IT systems • Insufficient analysis of design alternatives leads to subpar IT systems • Lack of documentation and external support leads to short-lived systems
The Right Tool for the Job • End users must have development tools that: • Are easy to use • Support multiple platforms • Offer low cost of ownership • Support a wide range of data types
PROTOTYPING • Prototype – a model of a proposed product, service, or system • Prototyping - the process of building a model that demonstrates the features of a proposed product, service, or system • Proof-of-concept prototype - prove the technical feasibility of a proposed system • Selling prototype - used to convince people of the worth of a proposed system
The Prototyping Process • The prototyping process involves four steps: • Identify basic requirements • Develop initial prototype • User review • Revise and enhance the prototype
Advantages of Prototyping • Encourages active user participation • Helps resolve discrepancies among users • Gives users a feel for the final system • Helps determine technical feasibility • Helps sell the idea of a proposed system
Disadvantages of Prototyping • Leads people to believe the final system will follow • Gives no indication of performance under operational conditions • Leads the project team to forgo proper testing and documentation
OUTSOURCING • Outsourcing – the delegation of specified work to a third party for a specified length of time, at a specified cost, and at a specified level of service • The third “who” option of systems development, after insourcing and selfsourcing
OUTSOURCING • The main reasons behind the rapid growth of the outsourcing industry include the following: • Globalization • The Internet • Growing economy and low unemployment rate • Technology • Deregulation
Outsourcing Options • IT outsourcing for software development can take one of four forms: • Purchase existing software • Purchase existing software and pay the publisher to make certain modifications • Purchase existing software and pay the publisher for the right to make modifications yourself • Outsource the development of an entirely new and unique system for which no software exists