MODELS Flashcards
What is layered technology?
Software engineering is a fully layered technology, to develop the software we need to go from one layer to the next. All the layers are connected and require the fulfilment to the previous layer.
The layered technology consists of?
Quality focus
Process
Methods
Tools
what is quality focus?
It provides providing security to the software so that data can be accessed by only an authorized person It also focuses on maintainability and usability.
what is process?
It is the foundation or base layer of software engineering. It binds all the layers together for the development of software before the deadline or on time.
Process defines a framework that must be established for the effective delivery of software engineering technology.
what are methods?
During the process of software development the answers to all “how-to-do” questions are given by method. It has the information of all the tasks.
what are tools?
automated support for the software dev.
they are integrated
base layer of software engineering
process
what is a software process model?
A software process model is an abstraction of software development process.
It specifies the stages and order of process.
It is a representation of the order of activities of the process and the sequence in which they are performed
what is SDLC model
it is the pictorial and diagrammatic representation of the life cycle of the software.
a methodology that defines the entire procedure of software development step-by-step.
SDLC in software engineering models outlines the plan for each stage so that each stage of the software development model can perform its task efficiently to deliver the software at a low cost within a given time frame that meets users’ requirements.
what is the need for SDLC?
Without using an exact life cycle model, the development of a software product would not be in a systematic and disciplined manner.
When a team is developing a software product, there must be a clear understanding among team representative about when and what to do. Otherwise, it would point to chaos and project failure.
steps of SDLC
STEP 1 planning and requirements analysis
STEP 2 defining req
STEP 3 designing the software
STEP 4 development
STEP 5 testing
STEP 6 deployment
STEP 7 maintenance
what is the most imp step in SDLC
planning and req analysis
what is SRS?
software req spec.
Here all the gathered req are documented and this document acts as a contract between the developer and the customer.
what is waterfall model
The steps always follow in order and do not overlap. The developer must complete every phase before the next phase begins. This model is named “Waterfall Model”, because its diagrammatic representation resembles a cascade of waterfalls.
what are steps of waterfall model
feasibility study
req analysis and gathering
design
coding and unit testing
integration and system testing
maintenance
what is classic waterfall model
The waterfall Model illustrates the software development process in a linear sequential flow. This means that any phase in the development process begins only if the previous phase is complete. In this waterfall model, the phases do not overlap.
what is iterative waterfall model
The iterative waterfall model provides feedback paths from every phase to its preceding phases, which is the main difference from the classical waterfall model.
When errors are detected at some later phase, these feedback paths allow correcting errors committed by programmers during some phase.
But, there is no feedback path to the stage – feasibility study
when is SRS formed?
in req analysis and gathering phase
when is SDD formed?
in design phase
what is SRS
it is formed during req analysis and gathering phase and is created to contain detailed description of what the system will do in common language
what is SDD
formed during design phase and all the work done here documented in SDD
when to use waterfall model
project is short
req are constant
situation is calm
advantages of waterfall model
req are constant
release date and costs can be determined before dev
disadvantages of waterfall model
high risk factor
cannot accept changes during dev
what is incremental model?
req are divided into various builds
multiple dev cycles take place here making the life cycle a multi-waterfall cycle.
cycles are div into smaller and easily managed modules
In this model, each module passes through the requirements, design, implementation andtestingphases. A working version of software is produced during the first module,. Each subsequent release of the module adds function to the previous release. The process continues till the complete system is achieved.
what are the phases of incremental model?
req analysis
design and implementation
testing
implementation
when to use incremental model
when req are superior
When Software team are not very well skilled or trained.
When the customer demands a quick release of the product.
disadv of incremental model
Needs good planning and design.
Total cost is higher thanwaterfall.
adv of incremental model
Generates working software quickly and early during the software life cycle.
Easier to manage risk because risky pieces are identified and handled during it’d iteration.
what is iterative model
In this Model, you can start with some of the software specifications and develop the first version of the software. After the first version if there is a need to change the software, then a new version of the software is created with a new iteration. Every release of the Iterative Model finishes in an exact and fixed period that is called iteration.
what is agile model?
combination of iterative and incremental process models
Agile Methods break the product into small incremental builds. These builds are provided in iterations. Each iteration typically lasts from about one to three weeks.
what are evolutionary process models?
Evolutionary modelis a combination ofIterativeandIncremental model
what are types of evolutionary process models
prototyping
spiral
what is prototype model?
The prototype model requires that before carrying out the development of actual software, a working prototype of the system should be built.
what is spiral model
it is a risk driven process model
combination of seq and waterfall model
In spiral model, an alternate solution is provided if the risk is found in the risk analysis, then alternate solutions are suggested and implemented.
In its diagrammatic representation, it looks like a spiral with many loops. The exact number of loops of the spiral is unknown and can vary from project to project.
what are dimensions of spiral model?
radial and angular
radial - cumulative costs
angular - progress made in completing in each cycle
each iteration in agile lasts?
1-3 weeks
which model is combination of iterative and incremental
agile
what is a iteration
each release of the iterative model finishes in an exact and fixed period called ietration
which model is comb of waterfall and seq
spiral
