Systems Development Life Cycle

• Failed systems are often abandoned because analysts attempt to build them without understanding the organization.
• The primary goal is to create value for the organization.
• Systems analysts are key individuals in analyzing businesses, identifying improvement opportunities, and designing information systems that implement ideas.
• Skills needed to successfully design and implement new information systems can be developed through practice.

Systems Development Life Cycle

• The project moves systematically through phases, each with a standard set of outputs.
• Project deliverables are produced, and these deliverables are then used in implementation.
• The life cycle results in an actual information system, which uses gradual refinement.

Project Phases

• Planning determines why the system is being built.
• Analysis addresses who, what, where, and when the system will be.
• Design focuses on how the system will function.
• Implementation involves system delivery.

Planning

• Planning involves identifying business value.
• Feasibility is analyzed.
• A work plan is developed.
• The project is staffed and controlled, and direction are established.

Analysis

• Analysis involves information gathering.
• Process and data modeling are performed.

Design

• Design includes physical, architectural, and interface design.
• Database and file design is included.
• Program design also forms part of the design phase.

Implementation

• Implementation encompasses construction.
• Installation of the system is also included.

Processes and Deliverables

• Planning results in a project plan.
• Analysis leads to a system proposal.
• Design produces a system specification.
• Implementation results in a new system and maintenance plan.

Methodology Defined

• Methodology is a formalized approach or series of steps.
• Writing code without a well-thought-out system request may work for small programs, but is rarely successful for larger ones.

Structured Design

• Projects move methodically from one step to the next.
• Generally, each step is completed before the next one begins.

Waterfall Development Method

• Planning, analysis, design, and implementation occur sequentially.

Pros and Cons of the Waterfall Method

• The waterfall method identifies system requirements long before programming begins, with the design specified on paper before programming.
• It often leads to a long time between system proposal and the delivery of the new system, however.

Alternatives to the SDLC

• Alternatives to the SDLC include Rapid Application Development (RAD).
• Phased Development is another alternative.
• Prototyping exists as an alternative.
• Throw-Away Prototyping also exists as an alternative.

Rapid Application Development (RAD)

• RAD critical elements include CASE tools, JAD sessions, fourth-generation/visualization programming languages, and code generators.

Rapid Application Development Categories

• Phased development involves a series of versions.
• Prototyping includes system prototyping.
• Throw-away prototyping involves design prototyping.

Object-Oriented Analysis and Design

• Object-oriented analysis and design attempts to balance emphasis on data and process.
• Unified Modeling Language (UML) is used for diagramming.
• It is also use-case driven and architecture-centric, and iterative and incremental.

Key Elements of Object-Oriented Systems

• Classes serve as templates to define objects.
• Instances are specific examples of class members.
• Objects serve as building blocks of the system.
• Attributes describe data aspects of the object.
• Methods define the processes an object can perform.
• Messages are instructions sent to or received from objects.
• Information hiding ensures that only necessary information for object use is accessible outside the object.
• Encapsulation combines data and processes into a single object.

Inheritance

• Inheritance allows objects to inherit attributes and methods from parent classes.

Polymorphism

• Polymorphism allows objects to respond differently to the same message, depending on their class.

UML Defined

• Full UML provides nine separate diagramming techniques.

Information System Roles

• Information system roles include business analyst.
• Information system roles include system analyst.
• Information system roles include infrastructure analyst.
• Information system roles include change management analyst.
• Information system roles include project manager.

Summary - Part 1

• The Systems Development Lifecycle includes planning, analysis, design, and implementation.
• There are three major development methodologies, namely: waterfall, RAD, and object-oriented approach.

Summary - Part 2

• Object-oriented design has six major elements: classes, objects, instances, attributes, methods, and messaging.
• Encapsulation, Inheritance and Polymorphism are important object-oriented concepts.
• The five major team roles are: business analyst, systems analyst, infrastructure analyst, change management analyst, and project manager.