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Information Systems
CSCI-N 100
Department of Computer and Information Science
Information Systems
An information system Collects data Stores data Processes data for organization
Useful information Accurate information Timely information
CEO
Finance HR Operations IS
Bookkeeper Accountant HR staff
Sales mgr Marketing mgr Warehouse mgr.
Sales staff
Artists Publicists
System Analysts Technicians Programmers Example of
Organizational Chart
Information Systems
Employees classified as Workers
Non-management positions Clerical Factory/general laborer Gather data for information system
Managers High-level Mid-level Low-level
Information Systems
ExecutiveStrategic planning
Mid-levelTactical planning
Low-levelOperational planning
Workers
Information Systems
Executive management Strategic planning
Determine organizational goals New products New construction Supervise workers
Plan long range goals Membership Profit
Information Systems
Mid-level mangers Tactical planning
Incremental goals One year or less
Plan on how to achieve long range goals Marketing Sales New products
Information Systems
Low-level managers Operational planning
Scheduling employees Ordering supplies Taking care of day-to-day business
Information Systems
Solving problems Structured
Collecting outstanding customer balances Unstructured
What do customers prefer Semi-structured
How much inventory to order
Information Systems – Transaction Process Point-of-sale
Items purchased at cash register Calculate total sales Verify credit cards
General accounting Tracking income Expenses Assets
Information Systems – Transaction Process Payroll systems
Track employee hours Calculate deductions, taxes Generate paychecks Generate W-2
Order-entry/Invoice systems Provide input, view, modify, delete orders Tracks order status Creates invoices
Information Systems –Management Information System (MIS)
System that uses collected data Manipulates data
Scheduled reports Set on preset timetable – day, week, month
Summary reports Annual sales - yearly
Exception reports Information outside normal ranges
Ad hoc reports Customized to supply specific information
Information Systems – Decision Support System (DSS)
Helps people make decisions Directly manipulates data Analyzes data from outside resources Generates statistical projections Create models
Tackles wide range of problems Does not make actual decisions
People analyze and decide
Executive Information System (EIS) Type of DSS
Used by senior managers Set policy Planning Budgeting
Supports decision maker Decision model
Numerical representation Cash flow
Decision query Instructions on data needed
Uses spreadsheets “what-if…”
Information Systems – Expert Systems
Also know as knowledge-based Designed to
Analyaze Produce a recommend Produce a diagnosis Produce decision
Rules designed are based on input from experts, incorporated into knowledge base Inference engine Knowledge engineering
Information Systems
Fuzzy logic Dealing with imprecise data
Weather
Neural network Simulates neural pathways of a brain Computer can “learn” to make decisions
Surveillance cameras in casinos, matching faces to known cheats
Information Systems – Systems Analysis
System Development Life Cycle Planning
Project development Analysis
System requirements Design
Application specifications Implementation
Working system Maintenance
Upkeep, upgrades
Information Systems – Systems Analysis
SDLC – System Development Life Cycle Information system development through
phases Project planning and development Analysis and system requirements Design and application specifics Implementation and working system Maintenance
Information Systems – Systems Analysis
Approaches Waterfall
One step at a time Modified waterfall
Accounts for overlap between steps Iterative
Repeats a phase as necessary
Information Systems – Systems Analysis
Project planning and development Scope of the project
PIECES Justification for project Teams Project schedule
Software PERT – Program Evaluation and Review
Technique WBS – work breakdown structure Ghantt Chart
Information Systems – Systems Analysis
Analysis and system requirements Study current system Determine requirements Report
Documentation tools Data flow diagram (DFD), how data moves through
the system UML (Unified Modeling Language)
Use case diagram Sequence diagram Class diagram
CASE tool (computer-aided software engineering)
Information Systems - Systems Analysis
Designing the system Identify solutions
Can have several, select the best one
Select hardware and software Consider the overall architecture of system
Software Selecting the best package
Application development tool Turnkey system
Request for proposal Describes problem and requirements for solution
Application specifications
Information Systems - Systems Analysis
Implementation – a working system Purchase/build software and hardware Test the applications
Application testing – checking results Unit testing – each module works Integration testing – modules work together
Final documentation System documentation – describes features architecture,
programming User documentation – instructions on how to use system
Information Systems – Systems Analysis(Implementation – a working system, cont’d.)
Convert data to new system Convert the system
Direct – immediate activation of new Phased – one module at a time Parallel – new an old running simultaneously Pilot – start in one location, then another
Information Systems – Systems Analysis
Maintenance System operator – backups, data recovery, trouble-
shooter System programmer – installs new upgrades to O/S
Upgrades to software or operating system User interface revisions Software revisions or upgrades
Bug fixes Security upgrades Hardware, software, and network adjustments for
optimal performance
Information Systems –Systems Analysis
(Maintenance, cont’d)
Quality of service Level of performance system provides
Metrics of QoS – for measuring and monitoring system Throughput – time interval for process of data Accuracy – errors in time interval Downtime – amount system unavailable Capacity – storage, users, connections User levels – number at peak/average/low levels Response time – time between request/response
Information Systems –Systems Analysis
(Maintenance, cont’d)
Length of maintenance phase Longest phase of SDLC Most expensive
End of maintenance phase?
Information Systems – Systems Analysis Data security
Common threats Natural disasters Power outages Hardware breakdown Human error Software failure Security breach War Viruses
Information Systems – Systems Analysis (Data security, cont’d.)
Information system data security Deterrents
Password protection Limited access
Preventive countermeasures Firewalls
Corrective procedures Redundant hardware
Detection activities Triggers countermeasures or detterents
Information Systems – Systems Analysis
(Data security, cont’d.)
Data centers
Specialized location for housing software and hardware for corporation
Underground Offsite
Disaster recovery plan Step-by-step plan
Ensure safety of people Continue operations Minimize disruptions Minimize danger, prevent further loss Management succession, emergency powers Coordinate recovery tasks
Information Systems – Systems Analysis
(Data security, cont’d.)
Corporate Identity Theft Name Logo Trademark
