1.1 - Systems in Organizations Flashcards
What is system life cycle and what are 5 stages of it?
System life cycle is the stages through which the development of a new system passes through.
Stages: inception, design, implementation, maintenance, and audit or disposal
What is SaaS?
SaaS (Software-as-a-Service), or “on-demand’’ software is a contemporary delivery method that allows software and data to be hosted and managed centrally on a remote datacenter.
It’s a way of delivering applications over the Internet—as a service
What is changeover?
Changeover is a process of putting the new system online and retiring the old one.
What are types of changeovers?
Parallel - both systems work in parallel for a short period of time (limited risks)
Big Bang or Direct (immediate) - company plugs in new system and unplugs the old one at the same time (very risky)
Pilot - mostly used in large organizations that have multiple sites. Pilot sites can serve as models (low risk) introducing the new system to one part of the company first and then rolling it out to other departments later.
Phased - a company converts one module of the system at a time, meaning that different parts of the system are converted at different times (takes longer)
Data migration
Transfer of data between different formats, storage types and computer systems. It happens when an organization changes, upgrades or merges its information systems.
Functional testing
Tests individual commands, text input, menu functions, etc. confirms that they perform and function correctly according to the design specifications.
Alpha testing
Done before the software product is made available to general public.
Beta testing
Comments and suggestions of the users, users outside of company are involved in the testing. Frequent beta testing results in last minute software changes.
Dry-run testing
conducted by pen-and-paper by the programmer who mentally runs the algorithm.
Unit testing
Individual parts of the system are tested separately.
Integration testing
Entire system is tested at the same time to verify that all components can work together.
User acceptance testing
Used to determine if the system satisfies the customer needs and is conducted in user premises before accepting transfer of ownership. This is the last stage of the software testing process.
Debugging
Systematic process of finding and correcting the number of bugs in a computer program.
Validation
Validation is the process of evaluating whether data input follows appropriate specification and is within reasonable limits.
Verification
Verification is the process of ensuring that the data input is the same as the original source data. A way of ensuring data verification is through double entry.
Verification and validation (not a question)
Verification is the confirmation that a computer product meets identified specifications, while validation is that a computer product meets its design functions or is appropriate for the intended use.
Internal and External documentation
A systematic and organized software development procedure ensures that all supporting documents are produced in an orderly and methodical fashion. It is very important to distinguish between internal documentation and external documentation.
Internal documentation is the code comprehension features and details provided as part of the source code itself. (e.g. Appropriate module headers, Appropriate comments, Useful and meaningful variable name, Useful module, classes, methods and function headers)
External documentation is typically written as a separate document from the program itself. It’s provided though user supporting documents such as guides, detailed description of the design and implementation features of the program and test document.
What is data loss?
Data loss - an error condition where data is lost or destroyed due to system failure, storage negligence, or even transmission or processing errors.
What are the causes of data loss?
Accidental deletion (very common, use the file recovery system) ; Administrative errors; Poor data storage organization system; Closing the program without saving the file; Computer viruses; Data corruption; Firmware corruption; Power failure
Redundancy
Redundancy is the duplication of the storage devices and stored data of a computer system with the intention of securing the stored data (failsafe method)
System failover
A system failover is a computer system which is on standby capable of switching to a spare computer system upon hardware failure, network failure, or any other type of error, such as software malfunction. The main difference between a failover and a switchover is the degree of needed human intervention.
