Systems Life Cycle & Analysis (SDLC & SAD) PDF

**SYSTEMS LIFE CYCLE** **System development life cycle (SLDC)** - conceptual model used in project management - stages involved in Information System (IS) development project - From initial study to maintenance **7 Phases of SDLC** 1. Planning 2. Analysis/Feasibility 3. Design 4....

**SYSTEMS LIFE CYCLE** **System development life cycle (SLDC)** - conceptual model used in project management - stages involved in Information System (IS) development project - From initial study to maintenance **7 Phases of SDLC** 1. Planning 2. Analysis/Feasibility 3. Design 4. Development 5. Testing 6. Implementation 7. Maintenance **6 Basic Types of SDLC Models** 1. **Waterfall Model** a. b. c. d. 2. **Iterative Model** e. f. g. h. 3. **Spiral Model** i. j. k. i. ii. iii. iv. 4. **V-Model** l. m. n. o. v. p. vi. 5. **Big Bang Model** q. r. s. vii. viii. ix. t. x. xi. u. xii. xiii. 6. **Agile Model** v. w. x. y. xiv. z. xv. xvi. xvii. xviii. xix. xx. xxi. **Benefits of System Life Cycle** - Enhances Product Quality - Improves Proejct Management - Manages Risk Effectively - Enhances Communication and Collaboration - Enables Efficient Resource Utilization - Flexibility and Adaptability **SYSTEMS ANALYSIS & DESIGN (SAD)** \- a structured approach used to develop, maintain, and improve IS systems **System Analyst** - Plan, develop, and maintain information systems - Manages IT projects, report to other dept **Benefits of SAD** - Improved Efficiency - Better Decision-making - Cost-savings - Alignment to Business Goals **Systems Development Life Cycle (SLDC)** 1. Planning 2. System Analysis 3. System Design 4. Implementation 5. Operation and Maintenance **Project Management in SAD** Key management components: 1. Scope 2. Time 3. Cost 4. Quality 5. Risk **Tools (to stay on track)** 1. Gantt charts 2. PERT diagrams 3. Project Management Software **Tools and Techniques in Systems Analysis** 1. **Data flow Diagrams** a. b. i. 2. **Entity-Relationship Diagrams (ERD)** c. d. 3. **Unified Modeling Language (UML)** e. f. ii. iii. iv. v. 4. **Use Case Diagram** g. 5. **Activity Diagram** h. 6. **Data dictionaries** i. j. 7. **Decision Trees** k. l. 8. **Decision tables** m. 9. **Pseudocodes** n. o. **Database Design in Systems Analysis** 1. Conceptual Design 2. Logical Design 3. Physical Design **System Security and Controls** 1. **Authentication** a. i. ii. iii. iv. 2. **Authorization** b. v. vi. vii. 3. **Encryption** c. viii. ix. 4. **Auditing** d. x. xi. xii. 5. **Disaster recovery** e. xiii. xiv. xv. 6. **Compliance** f. xvi. xvii. xviii. Ethical Considerations in SAD 1. **User Trust and Privacy** a. b. 2. **Compliance with Laws and Regulations** c. d. e. 3. **Stakeholder Interests and Impact** f. g. 4. **Consequences and Unintended Effects** h. 5. **Professional Integrity and Reputation** i. **Emerging Trends in SAD** 1. **Cloud Computing** a. b. i. ii. iii. 2. **Internet of Things (IoT)** c. d. iv. v. vi. 3. **AI and Machine Learning** e. f. vii. viii. 4. **Big Data** g. h. ix. x. xi. 5. **Mobile-first design** i. j. xii. xiii. xiv. **STRUCTURED ANALYSIS METHODOLOGY** \- uses graphical diagrams to develop and portray system specifications **Structured Analysis Attributes** 1. Graphical 2. Hierarchical 3. Logical 4. Modular **SA Benefits** 1. Improved communication 2. Early identification of issues 3. Enhanced system design 4. Reduced development time **SA Tools** 1. **Data flow diagram** a. b. 2. **Levels in DFD** c. d. e. f. 3. **Data Dictionary** g. h. i. ii. iii. i. iv. v. 4. **Decision trees** j. 5. **Decision tables** k. 6. Structured English l. 7. Pseudocodes m. **SA Major Process** 1. Study the current business environment 2. Modeling old logical system 3. Modeling new logical system 4. Modeling new physical environment 5. Evaluating alternatives 6. Selecting best design 7. Creating a structure specification **Techniques from the 3 Orthogonal Views (SA Process)** 1. **Functional View** a. 2. **Data view** b. 3. **Dynamic View** c. d. e. **Data Modeling** - creating a visual representation of org's data **DM Benefits** 1. Simplifies data 2. Avoid redundancy 3. Improved data integrity 4. Data sharing 5. Improved data reports **DM Model** 1. **Physical Data** a. 2. **Logical Data** b. **Input and Output Design** **Input design** - converting raw data from user to computer-based format. **ID Objectives** - Design data entry and input procedures - Reduce input volume - Design source documents for data capture or devise other data capture methods - Input data records, data entry screens, and user interface screens, etc. - Validation checks and input controls **Output Design** - systematic approach to defining, formatting, and delivering generated by a system to its user. **OD Objectives** - Provide accurate and reliable information - Meet user requirements - Facilitate decision making - Enhance usability and accessibility - Support multiple formats **Types of System Design** 1. **Logical** a. b. 2. **Phyisical** c. d. 3. **Architectural** e. f. 4. **Detailed** g. h. 5. **Conceptual Data Modelling** i. 6. **Entity Relationship** j. k.