Chapter 11 - System analysis methods

Question 1

Analysis (requirements of system to solve problem)

Answer 1

Data – origin, uses, volumes and characteristics
Procedures – what is done, how errors and exceptions are handled
Future – developments plans and expected growth rates
Problems – with any existing system

Question 2

Design

Answer 2

Processing – algorithms and modular structure for the solution, specifying modules with clear documentation
Data structures – how data will be held and accessed e.g. in a queue or database
Input/output - content, format, method used, etc.
User interface – dialogues, menus, etc.
Security – how to keep data secure

Question 3

Programming (modular programming, then coding) and testing

Answer 3

• Black box testing (functional testing) - create test data by looking at specification that covers all inputs, outputs and functions
• White box testing (structural testing) - creates test data by looking at structure that covers each possible path at least once
• Alpha testing – reveals errors and omissions in the specification (user may discover the system doesn’t have the required functionality)
• Beta testing – distribute software to potential users so that they can report any problems

Question 4

Implementation

Answer 4

Errors are traced and corrected
Then installed onto user’s system
More weaknesses and omissions will surface

Question 5

Evaluation

Answer 5

Critical examination of system 3-6 months after installation
Gives time for user and staff to get used to new system
Any new shortcomings will become apparent
Evaluated on basis of effectiveness, usability and maintainability

Question 6

The waterfall lifecycle model

Answer 6

Each step completed one at a time from beginning to end with specific outputs that lead into next step
Hard to return to previous stage (need to work down each stage again)
User involved at the start (analysis stage), then has little input until evaluation

Question 7

Spiral model

Answer 7

Same structured steps but done in iterative stages
Requirements are defined at the start and developers work towards an initial prototype
Each successive spiral produces a more refined prototype

Question 8

Agile modelling

Answer 8

Stages of software development not completed in a linear sequence
Feedback obtained from user throughout the process
Iterative process – changes made are incremental as next part of the system is built

Question 9

Extreme programming

Answer 9

Intended to improve software quality and responsiveness to changing customer requirements
Type of agile software where frequent releases are made in short development cycles
Intended to improve productivity and introduce checkpoints at which new customer requirements can be adopted

Question 10

Rapid application development (RAD)

Answer 10

Intended to complete major projects quickly without cancellations or restarting
Focus groups gather requirements, prototyping refines product, user feedbacks often
Producing within strict time limits, reusing any software components used elsewhere