3C: system documentation Flashcards
what do large software companies use as diagrams
stuff from the UML: united modelling language
other significant documentation during d + d
algorithms, pseudocode/flowcharts
test data + expected outputs
source code, internal + intrinsic
what is a model of a system
representation of that system designed to show structure + functionality
- most models in form of diagrams
why are diagrams useful
able to give broad view whilst also conveying necessary detail
function of system flowcharts
describes logic + flow of data through system, interactions between input, output, processing, storage
symbols used in flowcharts
function of context diagrams
represents entire system as a single process; identifies data entering + leaving system with its source + destination
how does a context diagram assist in understanding the problem
indicates where the new system interfaces with its environment, defined data + info that passes through each interface and direction of travel
function of data flow diagrams
describe path data takes through a system; roadmap, no timetables
- describes movement + changes in data between processes
DFD level system
level 0: specify external entities within system as a single process
level 1: expands level 0 into multiple processes
level 2: expands level 1 into multiple processes
and so on
- top-down design
what two processes can DFDs be used for
system analysis, understanding the problem
system design, plan + design
function of structure charts
used to model the hierarchy of subroutines, w/ the sequence in which these are to be executed
primary purpose of structure charts
create a template in preparation for actual source code; top-down, left to right
control meaning
the influence that causes tasks to execute in their correct sequence
function of IPOs
used to describe the data entering a process, the nature of the processing performed on the data, resulting information leaving the process
recommended method for drawing IPOs
three columns, one for input, process, output
function of data dictionary
repository which contains information on all variable names + identifiers
what should a data dictionary contain
a thorough description of each variable/data structure used, each field in each database, each file use/accessed
separate data dictionary made for module, database + files
what do screen designs provide
interface between user + software
what will a column in a data dictionary typically contain
- identifier
- data type
- format
- number of bytes
- size for display
- description/purpose
- example
- validation/range
- scope
screen designs + concept prototypes
concept prototypes used to implement screen designs for potential client feedback + gauge effectiveness
what do OS companies do
publish standards for screen design to ensure consistency between applications
CASE tools + screen designs
allow preferences to be set; when code generated, screens will adhere to preferences to encourage consistency
storyboard function
describes the screens used in a project, interaction with other screen
difference between movie + software storyboards
relationship between them; movie sequence is always linear, though software must also document flow of data
structure used by screen designs
top-down, hierarchal
