12 - software development

Question 1

library routines

Answer 1

are pretested functions/procedures ready for use

Question 2

program development lifecycle

Answer 2

the process of developing a program
analysis, design, coding, testing, maintenance

Question 3

analysis

Answer 3

investigation as to whagt is needed to be done and specification of what required

Question 4

design

Answer 4

uses spec to show hwo it shoudl develop

Question 5

waterfall model

Answer 5

each stage is completed and signed off before the next begins
+ easy to manage/ use
+ stages do not overlap and are completed one at a time
+ each stage has specific deliverables
difficult to change the requirements at a later stage
- not suitable for programs where the requirements could be subject to change
- working program is produced late in the lifecycle
- not suitable for long, complex projects

Question 6

iterative model

Answer 6

first develop a subset of the requirements then then the cycle again until the full system is developed - repeats waterfalls
+ quick to develop early stage
+ easier to debug smaller programs
+ more flexible
+ customers involved in each iteration
- need to define whole system to break it down
- needs to be good planning
- not for short projects

Question 7

RAD - Rapid Application Development

Answer 7

• develops different parts in parallel using prototyping to provide early involvement with the user
  + shorter time
  + frequent feedback
  + flexible
  + modification is easier as parts work separately
• need to be a modular system
• not for short projects

Question 8

structure chart

Answer 8

used to decompose a problem into sub tasks
shows a hierarchy of different modules and how they connect via oupits / input
each module is a box and parameters are arrows

Question 9

finite state machine

Answer 9

can be one of a fixed set of possibile states - states are changes by input

Question 10

state transition diagram

Answer 10

states are circles
transitions are arrows
events are labelled
conditions can be specified in []
initial state is an arrow with a black dot
the final state is a double cirle

Question 11

locating errors

Answer 11

• most IDEs flag syntax errors
• logic errors are found in testing
• can single step to find errors or manual work through a trace table

Question 12

run time errors

Answer 12

happen in the execution of the program
may halt unexpectedly or infinitely loop

Question 13

test plan

Answer 13

shows all stages of testing and how and when it should be tested
once tested add results to the test plan to show progress

Question 14

dry run

Answer 14

developer works through program manually wiht a trace table eg though pseudocode

Question 15

walkthrough

Answer 15

used predefined test cases where another member dry runs the pseudocode to check specific areas eg to test the calc use 20 + 10 = 30

Question 16

types of test data

Answer 16

normal data - acceptable
abnormal data - rejected
extreme data - on the limit
boundary data - within or just outside limits

Question 17

white box testing

Answer 17

involves testing the structure and logic of every path through a program

Question 18

black box testing

Answer 18

test inputs and outputs

Question 19

integrations

Answer 19

tests seperately written modules work together

Question 20

stub testing

Answer 20

used dummy modules to test whole code while certain modules aren’t finished yet
eg run whole code and once the add module is called it will output run add module

Question 21

alpha testing

Answer 21

the completed program is tested in house by the development team

Question 22

beta testing

Answer 22

tested by a small group of users

Question 23

acceptance testing

Answer 23

used for the completed program to prove to the customer it works in the required environment

Question 24

corrective maintenance

Answer 24

correct any errors that appear during use eg run time error missed in testing

Question 25

perfective maintenance

Answer 25

improve the performance of a program in its use eg improving speed

Question 26

adaptive maintenance

Answer 26

alter program so it can perform new tasks required by the user eg adding the ability for voice commands as well as text