Systems Development Life Cycle

Systems Development Life Cycle

1. Key Terms:

2. Concepts

   • a. Identify/Understand Consequences of Software (Systems) Success or Failure
     • 1. Increase or Decrease Revenues, 2.Repair or damage brand reputation, 3.Prevent or incur liabilities, 4. Increase or decrease productivity
   • b. Know the phases of the SDLC
     • SDLC Software Systems Development Life Cycle
       • A process used by software industry to design, develop and test high quality softwares.
       • 1. Planning Phase
         • What approach should I take? What are my goals? First and most critical phase
         • Understand the high-level differences among software development methodologies
           • Waterfall Methodology
             • In a waterfall model, each phase must be completed before the next phase can begin and there is no overlapping in the phases CONS:  1. Does not allow for much reflection or revision.  -Once an application is in the testing stage, it is very difficult to go back and change something that was not well-documented or thought upon in the concept stage. 
             • e. Agile principles
           • Agile Methodology
             • Iterative development: consists of a series of tiny projects Early continuous delivery of useful software components developed by an iterative process with a design point that uses the bare minimum reqs. 
             • FORMS OF THIS METHODOLOGY
               • Rapid Application Development (RAD) Methodology
                 • Fundamentals of RAD: 1. Focus initially on creating a prototype that looks and acts like the desired system -Prototype is an essential part of the analysis phase when using rad 2. Actively involve system users in the analysis, design, and development phases 3. Accelerate collecting the business requirements through an interactive and iterative construction approach
               • Extreme Programming Methodology (XP)
                 • Breaks a project into tiny phases and developers cannot continue on to the next phase until the first phase is complete. The faster the feedback the better the results Like a puzzle 4 parts. (1) planning (2) designing-no functionality until it is needed,  (3) Coding (4) Testing-tests are written before the code BENEFIT: -Narrows gap between developers and users ---->Saves time and clarifies needed and unneeded  reqs
               • SCRUM Methodology
                 • Small teams to produce small pieces of deliverable software using sprints, 30-day intervals, to achieve an appointed goal Standup meetings
       • 2. Analysis Phase
         • 1. Analyze end-user  business requirements-requests to be successful  2. Refine project goals into defined functions and operations of the intended system. Essential to getting a good start-So spend as much time, energy, and resources as necessary to perform a detailed, accurate analysis. What must the system do to meet the objectives? -Sign off-
       • 3. Design Phase
         • 1. Describe the desired features and operation of system
       • 4. Development (Construction) Phase
         • Takes all the detailed docs of the design phase and transforms them into the actual system. Project has come from preliminary designs to the actual physical implementation
       • 5. Testing Phase
         • You want to make sure that the system meets all the business reqs from analysis phase And Test in a special testing environment
       • 6. Implementation Phase
         • IMPLEMENT IT
         • Direct Conversion
         • Parallel Conversion
         • Phased Conversion
         • Pilot Conversion
       • 7. Maintenance
         • Maintain so that it continues to meet business goals Continues for life
   • Understand benchmarks for systems success
   • f. Project Management Applied to SDLC
     • 1. Unclear or missing business reqs-cost to fix an error grows exponentially the later the error is found in the SDLC 2. Skipping SDLC phases 3. Failure to manage project scope and project plan 4. Changing technology
     • i. Project Management Issues
       • i. Choose strategic projects
       • ii. Set the project scope
       • iii. Manage resources and maintain the project plan
       • iv. Change Management
       • v. Risk Assessment, Risk Management, Risk Mitigation
   • Understand the various types of feasibility
     • Technical Feasibility
     • Economic Feasibility
     • Legal Feasibility
     • Operational Feasibility
     • Scheduling Feasibility
   • Understand the key Implementation tasks and strategies
     • i. Train users
     • ii. Convert
     • iii. Benefits and Risks of conversion of different strategies
     • iv. Acceptance testing