Week3and4_sad.pptx

CSIT173- System Analysis and Design Prepared by: Glodelyn D. Ocfemia Introducti on to Systems Analysis and Design 1. Define the feasibility study that must consider before starting a project. 2. Discuss the different feasibility test 3. Illustrate the phases of System Anal...

CSIT173- System Analysis and Design Prepared by: Glodelyn D. Ocfemia Introducti on to Systems Analysis and Design 1. Define the feasibility study that must consider before starting a project. 2. Discuss the different feasibility test 3. Illustrate the phases of System Analysis and Design. 4. Demonstrate the use of modeling tools in understanding system design. OVERVIEW OF FEASIBILITY Week 3 OVERVIEW OF FEASIBILITY Feasibility study – is a study that determines whether a requested system makes economic and operational sense for an organization OVERVIEW OF FEASIBILITY OVERVIEW OF FEASIBILITY OVERVIEW OF FEASIBILITY FEASIBILITY TESTS: Operational FEASIBILITY TESTS: Operational FEASIBILITY TESTS: Operational FEASIBILITY TESTS: Operational 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 SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) 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 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 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 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 Phase 1: Planning 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: 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 Phase 2: Analysis 2.Prioritize the requirements Requirements definition document – prioritizes the business requirements and places them in a formal comprehensive document Phase 2: Analysis 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 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 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 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 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 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 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 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: 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 Requirements Modeling Week 4 Prepared by: Glodelyn D. Ocfemia Modeling Tools and Techniques Involves graphical methods and nontechnical language that represent the system at various stages of development Can use various tools Functional Decomposition Diagrams Functional decomposition diagram (FDD) Model business functions and show how they are organized into lower-level processes 34 Functional Decomposition Diagrams (sample) Modeling Tools and Techniques Business Process Modeling Business process model (BPM) Business process modeling notation (BPMN) Pool Swim lanes 36 Business Process Modeling (sample) Modeling Tools and Techniques Data Flow Diagrams Data flow diagram (DFD) show how the system stores, processes, and transforms data Additional levels of information and detail are depicted in other, related DFDs 38 Data Flow Diagrams (sample) Modeling Tools and Techniques Unified Modeling Language Widely used method of visualizing and documenting software systems design Use case diagrams Actor Sequence diagrams 40 System Requirements Checklist Outputs The Web site must report online volume statistics every four hours, and hourly during peak periods The inventory system must produce a daily report showing the part number, description, quantity on hand, quantity allocated, quantity available, and unit cost of all sorted by part number 41 System Requirements Checklist Inputs Manufacturing employees must swipe their ID cards into online data collection terminals that record labor costs and calculate production efficiency The department head must enter overtime hours on a separate screen 42 System Requirements Checklist Processes The student records system must calculate the GPA at the end of each semester As the final step in year-end processing, the payroll system must update employee salaries, bonuses, and benefits and produce tax data required by the IRS 43 System Requirements Checklist Performance The system must support 25 users online simultaneously Response time must not exceed four seconds 44 System Requirements Checklist Controls The system must provide logon security at the operating system level and at the application level An employee record must be added, changed, or deleted only by a member of the human resources department 45 Project Management Week 5 Project management helps teams organize, track, and execute work within a project. Project Management Process Project Management Process 5 Key benefits of project management