Studied by 18 people
System Life Cycle - Stages
Planning and Installation; Design; Building/Development; Implementation (changeover); Evaluation/maintenance/testing
Why are new systems created?
Minimize costs, increase productivity and/or reduce errors.
What are the different kinds of feasibility tests?
TELOS - Technical, Economic, Legal, Operational, Schedule
Change Management
Maximize benefits while making sure things go smoothy during a change from present state to desired state.
legacy system
an old system that is fast approaching or beyond the end of its useful life within an organization
Business Merger
The combining of two or more business entities.
Strategies for Integration
Keep both systems and develop them in parallel.
Replace both systems with a new one
Select the best systems from each company and combine them.
Select one company's system and drop the other
SaaS
Software as a Service; a subscription service where you purchase licenses for software that expire at a certain date.
On Premise Software
Software installed on buyer's computers
Change over
The process of putting the new system online and retiring the old one.
Types of Changeover (4)
Parallel Direct Pilot Phased
Parallel Changeover
a changeover approach that includes running the old system, then running both the old and new systems in parallel, and finally fully changing over to the new system after gaining confidence in the working of the new system
Direct Changeover
Immediate removal of an old system and complete replacement with a new IT system.
Pilot changeover
New system is trialed in a small part of business, once it's running correctly then new system is implemented across organisation
Phased changeover
a changeover approach where the older system is broken into deliverable modules; the first module of the older system is phased out using the first module of the new system, then the second module is replaced, and so on until the last module is replaced
Data migration
Transfer of data between different formats, storage types and computer systems.
Problems with Data Migration
Incompatible file formats Data structure differences Validation rules Incomplete data transfers International conventions on data, currencies & character sets (I [FF], DS, V, I, IC)
Fundamental Testing
Tests individual commands/text input to confirm that the program functions correctly according to design specs
alpha testing
the firm attempts to determine whether the product will perform according to its design and whether it satisfies the need for which it was intended, done before the product is released.
beta testing
A process that releases commercial software in development to a cross-section of typical users who evaluate the program's features and report any problems or "bugs" in the software before it is released to the public.
Dry Run Testing
Conducted with a pen-and-paper method by the programmer and he/she mentally runs the algorithm in the source code
Unit Testing
tests individual units of code
Integration Testing
The entire system is tested at the same time to verify that all components can work together.
User Acceptance Testing (UAT)
determine if the system satisfies the user and business requirements
Debugging
The process of figuring out why code doesn't behave as expected and eliminating bugs to make it work as desired.
Validation
The process of evaluating whether the data input is appropriate for the program.
verification
Ensuring that the data input is the same as the original source data. When reading from a source(file, db, etc) we make sure that we are reading the correct information.
Purpose of documentation
Providing users with information about how a system works. Informing other developers of reasons why code was included.
Internal Documentation
Inline code comments, code citations, class/functions headers
User Documentation
highlights how to use the system and how to troubleshoot issues or problems
Why is Proper Training Important?
Hard to take full advantage of new advanced technology Mistakes can be caused by not understanding the system thoroughly.
Types of User Training
Self Instruction Formal Classes Online Training
Data Loss Causes
System Failure, storage mistake, incompatible data, storage negligence, natural disasters, hacking.
How do you prevent data loss?
Regular backup of files Installation of antivirus/protective software.
redudancy
Refers to systems that are either duplicated or that fail over to other systems in the event of a malfunction
Removal Media
CD's, DVDs, USBs, portable SSDs, etc
Failover System
System which will take over the role of a primary system if it fails.
Patches
Updating applications to fix known bugs.
Updates
Improving the product by adding functionality or fixing bugs.
Software Release
The final version of the software that has gone through alpha and beta testing.
Software
A program or instructions that give directions to the computer.
Hardware
The physical components of a computer.
Peripheral device
Devices that communicate with the CPU but are not located directly on the motherboard, such as the monitor, floppy drive, printer, and mouse.
Computer Network
Computers connected together for the purpose of sharing information and resources
Human Resources
People who work to produce goods and services
Client
A person using the services of a professional person or organization.
Router
A device that transfers data from one network to another in an intelligent way
Firewall
Part of a computer system that is designed to block unauthorized access
Client server
Network system that uses servers to store data centrally and client computers to access them.
End User
The person or group who will use the product produced by the project.
External Documentation Forms
User Manuals Online Documentation Email Support Integrated User Assistance FAQ Live Chat Online Portals Remote Desktop Connections
Note 
Flashcard (102)