System Development Life Cycle (SDLC)

1. System Development Life Cycle (SDLC) CIS 105

2. Topics • List and describe the classic functions of managers: planning, organizing, directing, and controlling • Define “system,” “analysis,” and “design” • Describe the principal functions of the systems analyst • List and describe the phases of the systems development life cycle (SDLC) • Describe various data-gathering and analysis tools • List and describe various system testing methods • List and describe various system conversion methods

3. Classic Management Functions • Planning – devising plans for the organization and setting goals to achieve the plan • Organizing – deciding how to use the organization’s resources and includes hiring and training workers • Directing – guiding employees to perform their work in a way that supports the organization’s goals • Controlling – monitoring the organization’s progress toward reaching its goals

4. Levels of Management • Strategic level • Long range • Primary function: planning • Tactical level • Primary functions – organizing and staffing • Operational level • Primary functions – directing and controlling

5. System Development Life Cycle (SDLC) • Managers at each level need information to help them make decisions, so they rely on some type of Information System. • How are Information Systems purchased or built? • The process which includes analyzing the system requirements to designing and implementing a new system is called the System Development Life Cycle (SDLC).

6. Systems Analysis Design • System – an organized set of related components established to accomplish a certain task • Computer system – a system that has a computer as one of its components • Analysis - Studying an existing system to determine how it works and how it meets users’ needs • Typically happens as a result of some impetus for change, combined with the authority to make the change • Design - The process of developing a plan for an improved system, based on the result of the systems analysis

7. System Development Life Cycle (SDLC) • SDLC is an organized set of activities that guides those involved through the design, development, and implementation of an information system. • The number and names of each SDLC phase may vary by author and software company, but they all are very similar. • For this class, we will use the phases shown in this presentation. • The participants include technical staff, but also include non-technical business experts including end-users.

8. Users • Users are individuals that use a system to perform their jobs. • Users provide insight to the day-to-day business operations. • Users must be included from the beginning to the end so that they will feel some sense of ownership of the new system when it is implemented.

9. Who Participates? Project Team

10. Systems Analyst: A Change Agent • Systems analyst functions as the change agent. • The catalyst or persuader who overcomes the reluctance to change within an organization • What it takes: • Coordination of many people, tasks, and schedules • Communication skills, both oral and written • Planning and design (an analytical mind) • Self-discipline and self-direction • Good organizational skills • Creativity

11. Systems Development Life Cycle

12. Phase 1: Preliminary Investigation • A brief study of the problem to determine whether the project should be pursued • Usually launched by a formal project request. • Define the Problem • Set scope (boundaries) of the problem • One of the deliverables is the Feasibility Assessment. • Feasibility - measure of how suitable the development of a system will be to the organization.

13. Feasibility Assessment Report • Introduction – brief statement • Existing System • Background • Problems • Benefits of a New System • Feasibility of a New System • Operational • Schedule • Technical • Economic • Recommendation

14. Phase 2: Analysis • What is the definition of Analysis? • Studying an existing system to determine how it works and how it meets user’s needs. • What needs to occur so an analyst can determine how the current system works? • Gather and analyze data • From these findings, the system requirements for the new system can be determined.

15. Data Gathering Techniques • Review current system documentation • Interview users and managers • Structured interview – includes only questions that have been written out in advance • Unstructured interview – interviewer has a general goal but few, if any questions prepared • Questionnaires • Observation • Many of the reports, diagrams, and documentation are entered into the Project Notebook, Dictionary, and/or Repository.

16. Data Analysis • During this stage the problem definition is refined. • A detailed list of system requirements is created without regard to any specific hardware or software • Typical tools to represent data and procedures: • Entity Relationship Diagram (ERD) • Data Flow Diagram (DFD) • Decision table/Decision Tree • Report findings and recommendations to management

17. Systems Development Life Cycle - continued

18. Phase 3: Design • The new system is actually planned • Divided into two sub-phases • Preliminary design • High-level design • Decide to Build or Buy • Detail design specifications • Input and Output requirements • Design databases • Specific network and security needs • Develop Disaster Recovery Plans • May enter data into a CASE Tool to generate drawings and actual programming code • Computer Aided Software Engineering

19. Build Software Customized Developed in-house Developed by outside vendor Prototyping – limited function if any; shows what system may look like. Will be proceeding to Phase 4: Development Buy Software Prepackaged software Select software vendor Customization may be offered by software vendor for a price Will be proceeding to Phase 4: Testing Build or Buy?

20. Phase 4: Development • Scheduling • Define tasks and schedule • Use project management software to plan human resources and dependencies (see next slide). • Programming • Develop actual programs that make up the system • Each program is tested by the programmer. • Testing • Use various tests to evaluate entire system(Testing slide coming up…)

21. Project Management • The process of planning, scheduling, and controlling activities • Set scope (goal, objectives, expectations) • Activities and Deliverables to be completed • The order activities occur (some activities are concurrent and others are dependent) • Time and cost estimates Gantt Chart

22. Testing Types • Perform testing with predefined test data. • Unit testing – verifies that individual program units work. • System testing – determines whether all program units work together as planned. • Volume testing – uses real data in large amounts to see if system can handle it. • Load testing – used to determine if system can handle large number of concurrent users.

23. Phase 5: Implementation • Training – hands-on and user manuals • Equipment conversion – allow for delivery and installation • File conversion – manual to electronic, or system’s old format to new format • Auditing - need to be able to track data in system back to the source. • Evaluation – does system meet original requirements, benefits, and budget? • Maintenance – Fix bugs, enhancements, and new regulations • System conversion (see next slide)

24. System Conversion Options • Direct conversion – the user simply stops using the old system and starts using the new one • Parallel conversion – the old and new systems are both used until users are satisfied the new system works • Phased conversion – the system is implemented one part at a time • Pilot conversion – the entire system is used by a designated set of users

25. Systems Development Life Cycle - end

26. MCC Related Courses • CIS224 – Project Management • CIS225AB – Object-Oriented Systems Analysis and Design • CIS250 – Management Information Systems