Sofware Development Lifecycle

Question 1

What is the feasibility stage of development

Answer 1

The process of understanding what needs to be made and determines if it’s worth making the new software
Things considered are if the technology needed to make it exists yet
How much development of it will cost and how long will it take to earn that money back
Will there be any legal issues such as patents or copyright
How long will it take to develop

Question 2

What is the lifecycle of software

Answer 2

The development, use and replacement of software

Question 3

What happens in the analysis stage

Answer 3

The system analyst does this. The find out about the currant system the new one will replace and who is going to use it. With this infomation they will create the user requirements which the developer will use to make the system.a data dictionary will also be made to show the different variables, it tells its name, data type format and validation on it such as surname, string, capitals <25 charactera

Question 4

What happens in the design stage

Answer 4

This will include a plan on how to make it, using flowcharts and pseudo code. It will have the different inputs and outputs needed listed. Will have instructions on how the software will be tested to make sure it will be robust

Question 5

What happens in the implementation stage

Answer 5

The software is coded and tested
A written document is made on how to maintain the software for whoever has to support and maintain it.
Installing the software for the user

Question 6

What happens in evaluation stage

Answer 6

The customer will want to make sure the software does what it’s meant to so here, the software is compared to the user requirements to make sure it does what it needs to do

Question 7

What happens in the maintance stage

Answer 7

The software is kept well maintained
Unnoticed bugs are fixed, corrective maintenance
Software is updated to meet new user requirements, adaptive maintenance as it adapts to new requirements
Perfective maintenance may be done to may it easier to use and more perfect

Question 8

What are the three types of maintancence

Answer 8

CAP

Corrective adaptive perfective

Question 9

What is the waterfall model

Answer 9

A model of software lifecycle where to start a new stage, the previous one must be completed. You can return to stages but you have to go through all the ones between to reach there

Question 10

Advantages and disadvantages to waterfall model

Answer 10

Self contained and steps are easy to manage
Defined process and outputs for each step
Good model for managing many developers working together in parallel

Requirement changes mean going back to already completed stages
Changes are costly in time and money
Lack of customer involvement in analysis means issue not seen until evaluation
One of, once finished, no more new work done, just maintenance

Question 11

What happens in cyclical model

Answer 11

Each stage is done one at a time but instead of leaving it once it’s done, as soon as it’s finished, development for the next version starts such as for windows

Question 12

Advantages and disadvantages of cyclical model

Answer 12

Same as waterfall
Self controlled steps easy to manage
Defined process and outputs for each stage
Good model for managing large groups of developers as all go for one target
Maintenance starts the next stage, feasibility of next version

Requirement changes mean going back to completed ones
Changes costly and time consuming
Lack of customer involvements means issues only found in evaluation

Question 13

What happens in spiral model

Answer 13

First a prototype is made, this goes through all the stages of development. After it’s evaluated, the next prototype is made with more improvements. This keeps repeating until the final product is complete

Question 14

Stages of spiral model

Answer 14

Analyse to find requirements for new prototype
Implement, coding and testing new prototype
Evaluate, what is good at it, what is needed for next prototype

Question 15

Advatages and disadvantages of spiral model

Answer 15

Well defined steps make it easy to manage
Lots of prototypes means issues found quickly so final product will be best suited for customer
Iterative process means feedback can be easily obtained so next prototype can be improved

Each prototype takes a long time so very slow process
Long time means more expensive

Question 16

What is agile model

Answer 16

Similar to spiral but with heavy customer involvement. After each prototype, customer says what is good and bad about it

Question 17

Advantages and disadvantages of agile model

Answer 17

Same as spiral and also more flexible for quickly changing requirements

Question 18

Advantages and disadvantages of prototyping

Answer 18

Customer feedback means problems can be resolved before it is too far into development
Developer gets lots of meaningful feedback from customer for next prototype
Customer always satisfied at end as they helped design it

Expensive and time consuming
If customer is picky, it’s very slow

Question 19

What is the importance of testing

Answer 19

Testing makes sure the system is robust so the client shouldn’t be able to crash it. The program shouldn’t crash because of something the user typed in

Question 20

What are the six types of testing

Answer 20

Unit or module testing
Intégration testing
Intégration testing
Alpha testing
Beta testing
Acceptance testing
Creating a test plan

Question 21

What is unit/module testing

Answer 21

Large programs are often written in modules by different programmers. Each of these need to be tested before all the modules are out together. The developer will do several types of tests on their module such as trace tables

Question 22

What is intégration testing

Answer 22

Once all the modules are made, they are put together. The whole program with all the modules to make sure they all work together correctly

Question 23

What happens in alpha testing

Answer 23

Here someone Else in the company tests the program. Someone that wasn’t involved in making it so will be more likely to use it like the customer will to find unexpected errors

Question 24

What is beta testing

Answer 24

This is when the software is released to a few public early in return for feedback. This gets it thourally tested by lots of customers before it is commercially available

Question 25

What is acceptance testing

Answer 25

This is where the customer and developer go through a series of agreed tests to make sure it’s what the customer needs. This is when the developer usually gets paid