SIA

Legacy System

Outdated software and/or hardware that remains in use; often built for specific high-priority problems or productivity improvements, but can become difficult to operate or integrate as technology and business operations change.

Legacy System Issues

Security risks, high maintenance costs, technical debt, compliance gaps, and limited growth.

System Integration

Connects business processes, legacy platforms, new systems, COTS products, and external partners.

System

An array of components designed to accomplish an objective.

Systems Thinking

Understanding a part through its role in the larger whole — identifying the containing system, explaining the whole's behavior, and explaining the part's role in the whole.

System Architecture

The high-level organization of interacting components, connectors, properties, and styles.

Project

A temporary endeavor undertaken to create a unique product, service, or result.

Project Attributes

Unique purpose and temporary duration; requires resources from different areas; has a sponsor and/or customer; involves uncertainty.

Problems (project source)

Undesirable situations that prevent goals from being achieved.

Opportunities (project source)

Chances to improve revenue, service, profit, or costs.

Directives (project source)

Requirements imposed by management, government, or external forces.

Stakeholders

Sponsors, project teams, support staff, customers, users, suppliers, and opponents.

Project Success Factors

Executive support, user involvement, experienced project manager, clear objectives, controlled scope, sound infrastructure, firm requirements, methodology, and reliable estimates.

Functional Structure

Groups people with similar skills or tasks.

Divisional Structure

Organizes around products, customers, or geographic regions.

Matrix Structure

Combines functional and project reporting relationships.

Project-Based Structure

Teams are assembled around project needs.

Project Life Cycle

A collection of phases — Concept, Development, Implementation, Support — with management reviews after each to assess progress, success, and alignment with organizational goals.

Requirements

The essential needs a system must meet to provide value and utility; they guide analysis, design, implementation, evaluation, and integration, and describe what the system must do, not how it will be built.

Good Requirement Traits

Clear, atomic, unique, documented, owned, approved, traceable, necessary, complete, unambiguous, and testable.

Elicitation

Gathering ideas and candidate problems from relevant people.

Organization (requirements)

Classifying and categorizing requirements.

Analysis (requirements)

Transforming and refining requirements.

Prototype (requirements)

Testing poorly understood requirements and collecting feedback.

Documentation and Specification

Producing the formal requirements documents.

User Requirements

Natural-language statements and diagrams describing services and operational constraints.

System Requirements

Detailed system services agreed between client and contractor.

Functional Requirements

Inputs, outputs, stored data, computations, and timing.

Non-Functional Requirements

Constraints such as performance, reliability, security, cost, usability, and technology standards.

Fact-Finding Methods

Sampling, research/site visits, observation, questionnaires, interviews, prototyping, and JAD/JRP.

URS (User Requirements Specification)

Describes what the user expects; may include a Functional Requirements Specification (FRS).

SRS (System Requirements Specification)

A detailed description of agreed system services; often serves as a client–contractor contract.

Legacy System Integration

Connects modern applications with existing systems.

Enterprise Application Integration

Unifies subsystems within a business.

Third-Party System Integration

Expands an existing platform using external tools.

Business-to-Business Integration

Automates transactions and document exchange among organizations.

Integration Advantages

Improved information flow, efficiency, productivity, and service quality; less manual entry and reduced operational cost; better coordination across internal and external systems.

Integration Challenges

Security exposure can affect connected systems; complexity increases as systems change; implementation can be expensive and resource-intensive.