3. System development life cycle.ppt
- 1. McGraw-Hill/Irwin © 2008 The McGraw-Hill Companies, All Rights Reserved Chapter 6 Systems Development
- 2. 6-2 STUDENT LEARNING OUTCOMES 1. List the seven steps in the systems development life cycle (DSLC) and associated activities for each step. 2. Describe the four systems development methodologies. 3. Define the role of outsourcing.
- 3. 6-3 STUDENT LEARNING OUTCOMES 4. List and describe the three different forms of outsourcing. 5. Describe business process outsourcing (BPO). 6. Describe prototyping and profile an example of a prototype. 7. Describe the advantages of prototyping.
- 4. 6-4 Mercedes-Benz Online Built-to-Order Trucks • Mercedes-Benz allows customers to custom configure trucks online • Online program is called Truck Online Configurator
- 5. 6-5 Mercedes-Benz Online Built-to-Order Trucks • 5 months to create application • Including development, testing and installation • Phases would overlap • This approach is called rapid application development (RAD)
- 6. 6-6 Mercedes-Benz Online Built-to-Order Trucks • Class discussion… – Have you custom-ordered an auto? What was the process? Was it IT-enabled? – Why is custom ordering a competitive advantage? – What are some potential dangers of overlapping activities in any type of process?
- 7. 6-7 INTRODUCTION • Information systems are the support structure for meeting the company’s strategies and goals • New systems are created because employees request it • New systems are created to obtain a competitive advantage
- 8. 6-8 INTRODUCTION • Billions of dollars spent yearly on acquisition, design, development, implementation, and maintenance of IT systems • Companies depend on information more than ever
- 9. 6-9 SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) • Systems development life cycle (SDLC) - a structured step-by-step approach for developing information systems • Typical activities include: • Determining budgets • Gathering business requirements • Designing models • Writing user documentation
- 10. 6-10 SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) SDLC PHASE ACTIVITIES 1. Planning •Define the system to be developed •Set the project scope •Develop the project plan 2. Analysis •Gather business requirements 3. Design •Design the technical architecture •Design system models 4. Development •Build technical architecture •Build databases and programs 5. Testing •Write test conditions •Perform testing 6. Implementation •Write user documentation •Provide training 7. Maintenance •Build a help desk •Support system changes
- 11. 6-11 SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) • The SDLC has 7 phases: 1. Planning 2. Analysis 3. Design 4. Development 5. Testing 6. Implementation 7. Maintenance
- 12. 6-12 SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC)
- 13. 6-13 Phase 1: Planning • Planning phase - involves determining a solid plan for developing your information system • Three primary planning activities: 1. Define the system to be developed • Critical success factor (CSF) - a factor simply critical to your organization’s success
- 14. 6-14 Phase 1: Planning 2. 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
- 15. 6-15 Phase 1: Planning 3. 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
- 17. 6-17 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
- 18. 6-18 Phase 2: Analysis • Two primary analysis activities: 1. Gather the business requirements • Business requirements - the detailed set of knowledge worker requests that the system must meet in order to be successful • Joint application development (JAD) - knowledge workers and IT specialists meet, sometimes for several days, to define or review the business requirements for the system
- 19. 6-19 Phase 2: Analysis 2. Prioritize the requirements • Requirements definition document – prioritizes the business requirements and places them in a formal comprehensive document
- 21. 6-21 Phase 3: Design • Design phase - build a technical blueprint of how the proposed system will work • Two primary design activities: 1. Design the technical architecture • Technical architecture - defines the hardware, software, and telecommunications equipment required to run the system
- 22. 6-22 Phase 3: Design 2. Design system models • Modeling - the activity of drawing a graphical representation of a design • Graphical user interface (GUI) - the interface to an information system • GUI screen design - the ability to model the information system screens for an entire system
- 23. 6-23 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: 1. Build the technical architecture 2. Build the database and programs • Both of these activities are mostly performed by IT specialists
- 24. 6-24 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: 1. Write the test conditions • Test conditions - the detailed steps the system must perform along with the expected results of each step
- 25. 6-25 Phase 5: Testing 2. 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
- 26. 6-26 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 1. Write detailed user documentation • User documentation - highlights how to use the system
- 27. 6-27 Phase 6: Implementation 2. 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
- 28. 6-28 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
- 29. 6-29 Phase 7: Maintenance • Maintenance phase - monitor and support the new system to ensure it continues to meet the business goals • Two primary maintenance activities: 1. Build a help desk to support the system users • Help desk - a group of people who responds to knowledge workers’ questions 2. Provide an environment to support system changes
- 30. 6-30 SYSTEMS DEVELOPMENT METHODOLOGIES • Developers have different development methodologies: – Waterfall methodology – Rapid application development (RAD) – Extreme programming (XP) – Agile methodology
- 31. 6-31 Waterfall Methodology • Waterfall methodology - a sequential, activity- based process in which each phase in the SDLC is performed sequentially from planning through implementation
- 32. 6-32 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 the systems development process – Prototype - a smaller-scale, representation, or working model of the user’s requirements or a proposed design for an information system
- 34. 6-34 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
- 35. 6-35 Agile Methodology • Agile methodology - a form of XP, aims for customer satisfaction through early and continuous delivery of useful software components
- 36. 6-36 OUTSOURCING • Two primary choices to build IT systems (of great size and complexity): 1. Insourcing - involves choosing IT specialists within your organization to develop the system 2. Outsourcing - the delegation of specific work to a third party for a specified length of time, at a specified cost, and at a specified level of service
- 37. 6-37 OUTSOURCING
- 38. 6-38 OUTSOURCING • The main reasons behind the rapid growth of the outsourcing industry include the following: – Globalization and the Internet – Growing economy and low unemployment rate – Technology and deregulation • Request for proposal (RFP) – outsourcing document that informs vendors of your logical requirements
- 39. 6-39 Outsourcing Options • IT outsourcing for software development can take one of four forms: 1. Purchase existing software 2. Purchase existing software and paying the publisher to make certain modifications 3. Purchase existing software and paying the publisher for the right to make modifications yourself 4. Outsource the development of an entirely new and unique system for which no software exists
- 41. 6-41 Outsourcing Options • There are three different forms of outsourcing: 1. Onshore outsourcing - the process of engaging another company within the same country for services 2. Nearshore outsourcing - contracting an outsourcing arrangement with a company in a nearby country 3. Offshore outsourcing - contracting with a company that is geographically far away
- 42. 6-42 Offshore Outsourcing • Primary outsourcing countries are: – India – China – Eastern Europe (including Russia) – Ireland – Israel – Philippines
- 43. 6-43 The Advantages and Disadvantages of Outsourcing • Advantages: – Focus on unique core competencies – Exploit the intellect of another organization – Better predict future costs – Acquire leading-edge technology – Reduce costs – Improve performance accountability
- 44. 6-44 The Advantages and Disadvantages of Outsourcing • Disadvantages: – Reduces technical know-how for future innovation – Reduces degree of control – Increases vulnerability of your strategic information – Increases dependency on other organizations
- 45. 6-45 The Advantages and Disadvantages of Outsourcing
- 46. 6-46 Business Process Outsourcing (BPO) • Business process outsourcing (BPO) is using a contractual service to completely manage, deliver and operate one or more (typically IT or call center-intensive) business processes or functions
- 47. 6-47 Business Process Outsourcing (BPO)
- 48. 6-48 PROTOTYPING • Prototyping - the process of building a model that demonstrates the features of a proposed product, service, or system – Proof-of-concept prototype - used to prove the technical feasibility of a proposed system – Selling prototype - used to convince people of the worth of a proposed system
- 49. 6-49 The Prototyping Process • The prototyping process involves four steps: 1. Identify basic requirements 2. Develop initial prototype 3. User review 4. Revise and enhance the prototype
- 51. 6-51 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
- 52. 6-52 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
- 53. 6-53 END-USER DEVELOPMENT • End-user development (EUD) is the collection of techniques and methodologies for the creation of non-trivial software applications by end users • A successful strategy relies on two keys: 1. Knowing which applications are good candidates 2. Providing end users with the right tools
- 54. 6-54 Which Applications to Offload • Infrastructure-related • Mission-critical including ERP, CRM, Business Intelligence and e-business • High value to the enterprise not just a single line of business • Support large numbers of concurrent users’ for example, call center applications
- 55. 6-55 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
- 56. 6-56 The Right Tool for the Job • Not all end-user development is greatly accepted because of: – Version control – Low quality – Loss of control
- 57. 6-57 CAN YOU… 1. List the seven steps in the systems development life cycle (DSLC) and associated activities for each step. 2. Describe the four systems development methodologies. 3. Define the role of outsourcing.
- 58. 6-58 CAN YOU… 4. List and describe the three different forms of outsourcing. 5. Describe business process outsourcing (BPO). 6. Describe prototyping and profile an example of a prototype. 7. Describe the advantages of prototyping.