Comprehensive IT and Systems Analysis: Key Concepts and Frameworks

Information Technology (IT)

Combines hardware, software, and services to manage, communicate, and share information.

Systems Analysis and Design

Step-by-step process for developing high-quality information systems.

Systems Analyst

Plans, develops, maintains, and improves information systems.

Five Components of an Information System

Hardware, Software, Data, Processes, People.

Data

Raw facts used by a system.

Information

Data transformed into useful output.

Mission-Critical System

A system vital to company operations.

Stakeholders

People who have an interest in an information system.

B2C (Business-to-Consumer)

Businesses sell directly to consumers.

B2B (Business-to-Business)

Businesses sell products or services to other businesses.

C2C (Consumer-to-Consumer)

Consumers sell directly to other consumers.

Enterprise Resource Planning (ERP)

Systems supporting company-wide operations and data management.

Transaction Processing System (TPS)

Processes day-to-day business transactions.

Knowledge Management System

System using a knowledge base to provide information.

SDLC

Systems Development Life Cycle.

Five SDLC Phases

Planning, Analysis, Design, Implementation, Operations.

Structured Analysis

Development method using SDLC phases.

Object-Oriented Analysis

Combines data and processes into objects.

Agile Development

Incremental development with continuous user feedback.

Prototype

Early working version of a system.

Seven IT Department Functions

Application Development, Systems Support & Security, User Support, Database Administration, Network Administration, Web Support, Quality Assurance.

SWOT Analysis

Strengths, Weaknesses, Opportunities, Threats.

Strategic Planning

Identifying long-term goals, strategies, and resources.

Mission Statement

Reflects an organization's vision, purpose, and values.

Business Case

Justification for undertaking a project.

Systems Request

Formal request for IT support.

Six Reasons for Systems Requests

Stronger controls, reduced costs, more information, better performance, improved customer service, support for new products/services.

PESTEL Framework

Political, Economic, Social, Technological, Environmental, Legal factors.

Operational Feasibility

Will the system be used effectively?

Economic Feasibility

Do benefits outweigh costs?

Technical Feasibility

Can available technology support the system?

Schedule Feasibility

Can the project be completed on time?

Fishbone Diagram

Tool used to identify causes of a problem.

Project Scope

Specific boundaries of a project.

Project Creep

Unauthorized expansion of project scope.

Project Triangle

Cost, Scope, Time.

Work Breakdown Structure (WBS)

Breaks a project into smaller tasks.

Gantt Chart

Displays project schedules and progress.

PERT/CPM Chart

Shows task dependencies and relationships.

Milestone

A significant project event or completion point.

Critical Path

Tasks that determine the project completion date.

Slack Time

Time a task can be delayed without delaying the project.

Risk Management

Process of identifying, analyzing, and responding to risks.

Risk Response Strategies

Avoidance, Transfer, Mitigation, Acceptance.

ROI

Return on Investment.

System Requirement

A feature or characteristic needed in an information system.

Requirements Engineering

Process of gathering, representing, and validating requirements.

Functional Requirement

Describes what a system does.

Nonfunctional Requirement

Describes system constraints or performance requirements.

Requirement Challenges

Imprecision, Agreement, Feature Creep.

Scalability

System's ability to handle future growth.

TCO

Total Cost of Ownership.

JAD

Joint Application Development; team-based requirements gathering.

RAD

Rapid Application Development; iterative development emphasizing user involvement.

Requirements Elicitation

Gathering information and requirements.

Fact-Finding Techniques

Interviews, Observation, Document Review, Surveys, Brainstorming, Sampling, Research.

Observation Fact-Finding

Watching a system operate to verify procedures.

Brainstorming

Group discussion to generate ideas.

Agile Requirements Flow

Features → User Stories → Scenarios.

Use Case

Describes interaction between user and system.

FDD

Functional Decomposition Diagram.

BPM

Business Process Model.

UML

Unified Modeling Language.

Validation

Are the correct requirements stated?

Verification

Are the requirements stated correctly?

Traceability

Tracking requirements from origin through design, coding, and testing.

Logical Model

Shows what a system must do.

Physical Model

Shows how a system will be built.

Data Flow Diagram (DFD)

Shows how data moves through a system.

Four DFD Symbols

Process, Data Flow, Data Store, External Entity.

Process (DFD)

Transforms data into output.

Data Flow (DFD)

Path used to move data through a system.

Data Store (DFD)

Data saved for later use.

External Entity (DFD)

Source or destination of system data.

Source

Entity providing data to the system.

Sink

Entity receiving data from the system.

Context Diagram

Top-level DFD containing a single process (Process 0).

Diagram 0

Expanded version of Process 0 showing major processes and data stores.

Leveling

Creating more detailed DFDs.

Balancing

Keeping data flows consistent between DFD levels.

Data Dictionary

Repository of information about system data.

Data Element

Single data item or field.

Structured English

Simplified English used to describe process logic.

Decision Table

Shows all combinations of conditions and outcomes.

Decision Tree

Graphical representation of decision logic.

Three Logical Structures

Sequence, Selection, Iteration.

structured / waterfall

approach where each phase must be completely finished before the next one begins

black box (hole)

the process’s inputs, outputs, and functions are known, but underlying logic is hidden

attributes

are characteristics that describe the object