1.5 Alternative Development Approaches Q

Question 1

Describe the main features of RAD

Answer 1

Barbara doesn’t pick apple trees.

1) business modelling- determine how information flows in a business
2) data modelling- data objects identified and defined and relations between data objects are established.
3) process modelling- process descriptions for making any kind of addition/ modification to a data object or the retrieval of a data object identified at this stage.
4) application generation- actual system is developed using automated tools used to generate code for the final application.
5) testing and turnover- prototypes tested at end of each iteration, overall testing time reduced in RAD, however the application interface and data flow between components must be tested thoroughly.

Question 2

Describe main features of agile

Answer 2

Combination of iterative (waterfall) and incremental (rad).
Aim- rapid delivery of a working product in response to customer needs.

Method- divided into small incremental tasks provided in iterations- stages.
During each iteration a series of teams will work on modules concurrently.

Question 3

Compare and contrast the use of the agile development approach with RAD

Differences

Answer 3

Definition of RAD
DEF OF AGILE
SIMILARITIES
DIFFERENCES- rad creates prototypes of whole system whereas agile involves the project being worked on in modules simultaneously.

Agile- involves more client involvement and the build can be changed at any time as the client clarifies user requirements.

With RAD- project split into stages, each of which the client feeds back on

Question 4

Evaluate the use of waterfall method in this case (context)

Disadvantages

Answer 4

Advantages

DISadvantages- once testing begins amendments to system requirements can not be made easily.
No SW produced until late into development process so high level of risk involved.

Question 5

Evaluate the use of RAD method in this case (context)

Disadvantages

Answer 5

Advantages-

Disadvantages- not suited to all systems
Expensive approach due to use of automated code generation and modelling tools.
Used existing components/ code generation so finished SW might not be fully bespoke.

Question 6

Business modelling

Answer 6

Determines how information flows in a business

Question 7

Data modelling

Answer 7

Data objects identified and defined and relation between data objects are established.

Question 8

Process modelling

Answer 8

Process descriptions for making any kind of addition/ modification to a data object or
Retrieval of a data object identified at this stage.

Question 9

Application generation

Answer 9

Actual system developed using automated tools to generate code for final application

Question 10

Testing and turnover

Answer 10

Prototypes tested at end of each iteration
Overall time reduced in rad
However
Application interface and dataflow between components must be tested thoroughly.

Question 11

Definition of agile

Answer 11

combination of W+r- incremental modules worked on in iterations concurrently

Question 12

Definition of RAD

Answer 12

Crates a series of prototypes in quick succession.

Different stages of development can happen at any time

incremental model- project subdivided into series of builds- components of system developed in parallel- produce prototypes delivered to user for feedback

Question 13

Compare and contrast the use of the agile development approach with RAD

Similarities

Answer 13

DEF OF RAD
DEF OF AGILE

both reduce development time ( both faster delivery than waterfall)
Both work in stages
Both allow user/ customer feedback to meet change in user requirements.

DIFFERENCES

Question 14

Evaluate the use of waterfall method in this case (context)

Advantages

Answer 14

Advantages- rigid model with specific outcomes- easy to understand.
Works well with small projects where requirements are clear.
Easy to schedule because of distinct stages.
No overlapping of phases so easy to implement.

Disadvantages

Question 15

Evaluate the use of RAD method in this case (context)

Advantages

Answer 15

Advantages- reduction in development time
Components reviewed at an early stage
Client feedback encouraged
Components can be reused

Disadvantages

Question 16

Waterfall method

Answer 16

Consists of sequence of discrete stages- stage must be compiled before next starts.

Deliverables produces at end of each stage.

Earlier stage may be revisited if an error found during later stage.

Each stage can only start when the previous stage has finished.

Review at end of each stage

Question 17

Advantages of waterfall

Answer 17

Linear process therefore easier to understand.

Stages don’t overlap so easy to schedule.

Documentation produced at end of most stages- clients find this reassuring.

Work well In small projects where user requirements are clear.

Question 18

Disadvantages of waterfall

Answer 18

Changes to requirements cannot be made after the system is designed
INFLEXIBLE

software not produced until quite late on so there is a risk that it might not be acceptable to the client.