BUSINESS INFORMATION SYSTEMS – CORE EXAM NOTES

Cloud Computing

Cloud services deliver on‐demand, scalable IT resources via the Internet, shifting CAPEX to OPEX and enabling rapid deployment. Key benefits include lower upfront cost, elasticity, ubiquitous access, automatic updates, and a pay-per-use model; limits entail security dependence on the provider, possible latency, compliance constraints, and data-sovereignty issues. Major trends: hybrid/multi-cloud strategies, containerisation, serverless functions, edge computing, AI-as-a-Service, and stricter governance frameworks.

Core Information-System Concepts

A Business Information System (BIS) converts data into high-quality information to support operational, tactical, and strategic activities. Its resources are people, hardware, software, data, and communications, orchestrated through input, processing, output, storage, and control. BIS value is assessed via improved decision quality, cost reduction, process speed, and competitive advantage.

Data–Information–Knowledge–Wisdom (DIKW)

• Data = raw facts, $\textit{datum}$ being a single fact.
• Information = processed data in context, produced for a purpose and reducing uncertainty.
• Knowledge = the utilisation of information plus experience and intuition (explicit vs tacit).
• Wisdom = the ability to apply knowledge soundly to novel situations.

Information Quality Attributes

Time (timeliness, currency, frequency, period), Content (accuracy, relevance, completeness, conciseness, scope), and Form (clarity, detail, order, presentation, medium). High-quality information is reliable, secure, machine-readable, and verifiable.

Managerial Decision-Making

Decisions range from structured (programmable) to unstructured (non-programmable) across operational, tactical, and strategic levels. Fayol and Weber emphasised planning, control, and bureaucracy; decision behaviour depends on cognitive style (analytical vs intuitive). Tools: business rules, decision trees/tables, and pseudocode embed logic into BIS.

Systems Theory Basics

A system comprises input, process, output, feedback, and control, bounded within an environment and interacting via interfaces. Subsystems are loosely coupled for flexibility; systems may be deterministic/probabilistic, hard/soft, adaptive, open/closed, and hierarchical.

Information-System Architectures

Client/Server and peer-to-peer models dominate. Resources are shared over LANs, WANs, intranets, extranets, and the Internet; protocols follow the $\text{TCP/IP}$ and $\text{OSI}$ stacks. Cloud and virtualisation extend capacity; firewalls, VPNs, and encryption secure data flows.

Hardware Essentials

CPU executes instruction and execution cycles at $\text{GHz}$ speeds; cache ($L1$–$L3$) bridges RAM and registers. Processor families: x86, ARM, multicore, parallel, grid, and cloud nodes. Memory: volatile $\text{RAM}$, non-volatile $\text{ROM/EEPROM}$, plus cache. Storage: magnetic (HDD, RAID), optical (DVD, Blu-ray), solid-state (SSD, flash). I/O: keyboards, pointing devices, scanners, sensors, displays, printers.

Software Building Blocks

Systems software (OS, utilities, middleware) manages hardware, files, security, UI, multitasking, and networking. Application software supports productivity, collaboration, and analytics. Trends: mobile OSs (Android, iOS), open-source Linux, virtualisation, and SaaS.

Databases & Business Intelligence

Relational DBMS store data in linked tables via primary/foreign keys; SQL enables querying. Data warehouses integrate historical data; ETL pipelines populate warehouses; OLAP cubes and dashboards provide multidimensional analysis. Data mining uncovers associations, sequences, classification, clustering, and predictive models; BI converts patterns into actionable insight.

Networks & E-Commerce

LANs use twisted-pair, fibre, Wi-Fi; WANs rely on leased lines, satellites, VPNs. Internet services (HTTP, HTTPS) support B2B, B2C, C2C, and e-government models; payment systems employ digital certificates and PCI standards. Benefits: global reach, lower costs, personalisation; challenges: security, privacy, trust, logistics.

Systems Development Life Cycle (SDLC)

Phases: Investigation → Analysis → Design → Development → Implementation → Maintenance → Retirement. Tools include feasibility studies, data-flow diagrams, ER models, decision tables, Gantt/PERT charts, and CASE. Alternatives: prototyping, RAD, end-user development, outsourcing. Feasibility spans technical, economic, operational, and organisational dimensions.

Rapid Application Development (RAD)

RAD counters long SDLC cycles via iterative prototyping, user involvement, component re-use, and time-boxed delivery. DSDM, Agile, and Scrum exemplify RAD: evolving requirements, frequent releases, and cross-functional teams.

Key Exam Reminders

• Convert data → information by context, purpose, and processing.
• Quality info = $\text{accurate} + \text{timely} + \text{relevant}$.
• Structured ↔ unstructured decisions map to operational ↔ strategic levels.
• Primary key uniquely identifies; foreign key links tables.
• CPU performance depends on $\text{clock\ speed}$, cores, cache, bus.
• HTTP runs over $\text{TCP/IP}$; HTTPS adds SSL/TLS encryption.
• SDLC ensures disciplined development; RAD/Agile adds flexibility.
Review diagrams: DIKW pyramid, system IPO model, ER & DFD symbols, OSI layers.