BUILDING ANALYSIS MODEL Flashcards
what is building analysis model?
it is a set of models and the first technical representation of the system
a written document is good but not the best way to represent the req
analysis model uses a combination of text and diagrammatic forms to depict requirements for the system in a way that is easy to understand.
who makes the analysis model?
software engineer called an analyst
why it analysis model important?
It’s important to validate software requirements by looking at them from various angles. Analysis modeling helps represent requirements in different ways to understand the requirements.
what is a work product?
consists of various diagrammatic forms. Each type of diagram offers a perspective on one or more elements of the model.
what are steps of req analysis?
Draw the context diagram
develop a prototype
model the req
finalize the rq
what does draw the context diagram means?
it is a simple model that defines the boundaries and connections of the system with the external world.
it identifies the entities outside of the system that interact with the system
what does develop a prototype means?
One effective way to find out what the customer wants is to construct a prototype, something that looks and preferably acts as part of the system
We can use their feedback to modify the prototype until the customer is satisfied continuously.
what does model the req means?
This process usually consists of various graphical representations of the functions, data entities, external entities, and the relationships between them. The graphical view may help to find incorrect, inconsistent, missing requirements.
what does finalize the req means?
After modeling the requirements, we will have a better understanding of the system behavior. The inconsistencies and ambiguities have been identified and corrected.
Now we finalize the analyzed requirements, and the next step is to document these requirements in a prescribed format.
what are concepts of data modeling?
data objects
relationships
cardinality and modality
what are data objects?
A data objects is a representation of almost any composite information i.e. something that has a number of different attributes.
what are relationships?
Data objects are connected to one another in different ways.
Consider the two data objects person and car.
A person owns a car
A person is insured to drive a car.
what is cardinality?
We must understand how many occurrences of object X are related to how many occurrences object Y. This leads to data modeling concept called “cardinality”.
what is modality?
The modality of a relationship is 0 (Zero) if there is no explicit need for the relationship to occur or the relationship is optional. The modality is 1 (one) if an occurrence of the relationship is mandatory.
when modality is 0?
need need for relationship/optional
when modality is 1
relationship is mandatory
What is flow oriented modeling?
The flow oriented modeling represents how data objects are transformed at they move through the system.
flow models use the data flow diagram, depicts how input is transformed into output as data objects move through the system.
follows a top to down methodology
The modeling tools that are used to build a data flow oriented model?
DFD
What is DFD
Data flow diagram
define DFD
The data flow diagram represents the flows of data between different process in a business.
It is a graphical technique that depicts information flow and transformations that are applied as data changes from input to output.
The flow of data of a system or a process is represented by DFD.
what are components of DFD
process
data flow
data store
external entity
what is a process?
An activity
that changes or transforms data flows.
they transform incoming data to outgoing data
representation of a process?
circle
what is a data flow ?
The labeled arrows indicate incoming and outgoing data flow
what is data store
A data store does not generate any operations but simply holds data for later access.\
represents external activity
symbol of data store
parallel lines
what is external entity
In Data Flow Diagrams external entities produce and consume data that flows between the entity and the system being diagrammed.
symbol of external entity
rectangle
what are the levels of DFD?
0
1
2
3
what is 0 level dfd?
It represents the entire system as a single bubble and provides an overall picture of the system.
also known as context diagram
what is 1 level dfd?
This elaborates level a DFD and splits the process into a detailed form.
what is 2 level dfd?
This elaborates level 1 DFD and displays the process(s) in a detailed form.
what is level 3 dfd?
This elaborates level 2 DFD and displays the process(s) in a detailed form.
