Summary ICT2622 SUMMARISED NOTES 2022/2023

ICT2622 SUMMARISED NOTES 2022/2023 1 Contents Chapter 1: An overview of systems analysis and design ...................................................................................................................... 5 What is an information system? ............................................................................................................................... 5 What is a computer application (app)? .................................................................................................................... 5 Define systems analysis ............................................................................................................................................ 5 Define systems design .............................................................................................................................................. 5 The Systems Development Life Cycle (SDLC) ............................................................................................................ 5 Define iterative development................................................................................................................................... 5 Chapter 2: Investigating System Requirements ................................................................................................................................ 6 Systems Analysis Activities ....................................................................................................................................... 6 System requirements ............................................................................................................................................... 6 Define system requirements ................................................................................................................................ 6 Categories of requirements .................................................................................................................................. 6 FURPS framework ................................................................................................................................................. 6 FURPS+ .................................................................................................................................................................. 6 Stakeholders ............................................................................................................................................................. 7 Define stakeholders .............................................................................................................................................. 7 Types of stakeholders ........................................................................................................................................... 7 Information Gathering Techniques .......................................................................................................................... 7 Interview users and other stakeholders ............................................................................................................... 7 Questionnaires...................................................................................................................................................... 8 Review inputs, outputs and procedures ............................................................................................................... 8 Observe and Document Business Processes ........................................................................................................ 8 Research Vendor Solutions ................................................................................................................................... 8 Collect active user comments and suggestions .................................................................................................... 8 Chapter 3: Identifying User Stories and Use Cases ............................................................................................................................ 9 Why is identifying user stories and use cases the key to defining functional requirements? ................................. 9 Briefly explain user stories and acceptance criteria ................................................................................................. 9 2 Techniques to identify Use Cases .......................................................................................................................... 9 a) User Goal Technique ........................................................................................................................................ 9 b) Event Decomposition Technique .................................................................................................................... 10 Notation and Purpose for the use case diagram .................................................................................................... 12 Notation: ............................................................................................................................................................. 12 Chapter 4: Domain Modeling .................................................................................................................................................... 14 Explain how the concept of “things” in the problem domain also defines requirements ..................................... 14 What is the problem domain? ............................................................................................................................ 14 2 What are “things”? ............................................................................................................................................. 14 How “things” in the problem domain also define requirements: ...................................................................... 14 Briefly describe two techniques for identifying the important things in the problem domain that the system needs to remember: ............................................................................................................................................... 14 a) The Brainstorming Technique ........................................................................................................................ 14 b) The Noun Technique ...................................................................................................................................... 14 The Entity-Relationship Diagram ............................................................................................................................ 15 What is an entity-relationship diagram? ............................................................................................................ 15 Domain Model Class Diagram................................................................................................................................. 16 Notation .............................................................................................................................................................. 16 Types of relationships ......................................................................................................................................... 17 The State Machine Diagram ................................................................................................................................... 17 Define a state ...................................................................................................................................................... 17 Define a transition .............................................................................................................................................. 17 Define a state machine diagram ......................................................................................................................... 18 Describe the difference between a class diagram and a state machine diagram: ............................................. 18 Terminology regarding state machine diagrams: ............................................................................................... 18 Notation: ............................................................................................................................................................. 18 Naming transitions ............................................................................................................................................. 18 8 Steps to develop State Machine Diagrams (SMD): .......................................................................................... 19 Chapter 5: Use Case Modeling .................................................................................................................................................. 20 Use Case Descriptions............................................................................................................................................. 20 Terminology: ....................................................................................................................................................... 20 Activity Diagrams for Use Cases ............................................................................................................................. 21 The System Sequence Diagram .............................................................................................................................. 22 Briefly explain what a system sequence diagram is ........................................................................................... 22 Notation .............................................................................................................................................................. 22 4 Steps to developing a System Sequence Diagram (SSD) based on an activity diagram .................................. 22 CRUD Technique ..................................................................................................................................................... 23 4 Steps included by the CRUD technique for validating and refining use cases ................................................ 23 How do use case descriptions and UML diagrams work together to define functional requirements? ............... 23 Chapter 9: Designing the Database ............................................................................................................................................ 24 What is a database? ............................................................................................................................................... 24 What is a database management system? ............................................................................................................. 24 Components of a database ..................................................................................................................................... 24 Database data: .................................................................................................................................................... 24 Database Management System: ......................................................................................................................... 24 What is SQL? ....................................................................................................................................................... 24 3 The Data Administrator (DA) .................................................................................................................................. 24 The Database Administrator (DBA) ........................................................................................................................ 24 Relational Databases .............................................................................................................................................. 24 The Relational Database Management System (RDBMS) .................................................................................. 24 Terminology ........................................................................................................................................................ 25 9 Steps to creating a relational database schema from a domain model class diagram ....................................... 25 Creating a table ................................................................................................................................................... 26 Choosing primary keys ........................................................................................................................................ 26 Representing associations .................................................................................................................................. 26 Representing classification hierarchies .............................................................................................................. 26 Enforcing referential integrity ............................................................................................................................ 26 Database Normalization ......................................................................................................................................... 26 Briefly explain normalization .............................................................................................................................. 26 First normal form (1NF) ...................................................................................................................................... 26 Second normal form (2NF) ................................................................................................................................. 26 Third normal form (3NF) ..................................................................................................................................... 27 Distributed Database Architectures ....................................................................................................................... 27 Decentralized database: ..................................................................................................................................... 27 Homogenous distributed database: ................................................................................................................... 27 Heterogenous distributed database: .................................................................................................................. 27 Implementation Approaches for Distributed Database ......................................................................................... 27 Data Replication.................................................................................................................................................. 27 Horizontal Partitioning ....................................................................................................................................... 27 Vertical Partitioning ............................................................................................................................................ 28 Combination of Replication, Horizontal- and Vertical Partitioning .................................................................... 28 Protecting the database ......................................................................................................................................... 28 Transaction Logging ............................................................................................................................................ 28 Chapter 10: Approaches to System Development ............................................................................................................................. 29 Predictive Approach ............................................................................................................................................... 29 Adaptive Approach ................................................................................................................................................. 29 What makes up a system development methodology? ......................................................................................... 29 Methodologies .................................................................................................................................................... 29 Models ................................................................................................................................................................ 30 Tools.................................................................................................................................................................... 30 Techniques .......................................................................................................................................................... 30 How do methodologies, models, tools and techniques fit together? ................................................................ 30 Describe the key features of Agile Development ................................................................................................... 30 Key Features ....................................................................................................................................................... 30 4 12 Agile Modeling Principle ................................................................................................................................ 31 4 Basic Values of Agile Development ................................................................................................................. 33 Describe the key features of the Unified Process .................................................................................................. 33 4 Unified Process Phases .................................................................................................................................... 33 Complete the beta test and deployment so users have a working system and are ready to benefit as expected. Unified Process Disciplines ................................................................................................................ 34 Extreme Programming (XP) .................................................................................................................................... 34 XP Core Values .................................................................................................................................................... 34 XP Practices ......................................................................................................................................................... 34 Scrum ...................................................................................................................................................................... 35 Philosophy .......................................................................................................................................................... 35 Organization ....................................................................................................................................................... 35 Practices .............................................................................................................................................................. 35 Chapter 12: Object-Oriented Design: Fundamentals .......................................................................................................................... 36 Purpose and Objectives of Object-Oriented Design ............................................................................................... 36 Class Responsibility Collaboration (CRC) Cards .................................................................................................. 36 What is object-oriented design? ........................................................................................................................ 36 Design Class Diagrams ............................................................................................................................................ 36 Stereotype .......................................................................................................................................................... 36 Notation .............................................................................................................................................................. 38 CRC Cards ................................................................................................................................................................ 38 Fundamental Principles for Good Design ............................................................................................................... 39 Object Responsibility .......................................................................................................................................... 39 Separation of Responsibilities ............................................................................................................................ 39 Protection from Variations ................................................................................................................................. 39 Indirection........................................................................................................................................................... 39 Coupling .............................................................................................................................................................. 39 Cohesion ............................................................................................................................................................. 39 Chapter 13: Object-Oriented Design: Use Case Realization ................................................................................................................... 40