What is a system?
Input –> Process –> Output –> Feedback (continuous loop)
Input– Anything that goes into the system
Process– The process that results in the output
Output– The result of the process
Feedback– Information from the previous cycle used to change the process in proceeding cycles
System enviroment
system boundary- defined by the rules placed on the particular system, often difficult to define the exact boundaries of a system
input- Only occurs in open systems, any information that is put into a process
output- The result from the process
feedback- Information gathered from an output used to change the way/choices the system makes the next time it runs.
control- ???
May also have
Emergent properties-
Interfaces to other systems-
Sub-systems- Systems that operate separately from the main system
Different processes
Online– The application receives instructions and completes them eg. when surfing the net
Real time– The application needs to respond to requests in a certain amount of time, usually seconds eg. airplane controls
Batched– The application saves the requests and processes them at an off-peak time eg. overnight banking
Different systems
Open system– A system with input, it changes its behavior according to conditions outside its boundary
Closed system– A system with no input, it doesn’t interact with the enviroment
SDLC– System/software development life cycle, the process used to develop/upkeep a system/software
Cause and effect
One point of reference changing will cause a chain reaction where the system reshuffles to make everything work