Info 3- systems development tools and techniques

Investigating and recording techniques
Interviews
Joint application development (JAD)- group of people get together and stay in session until complete set of requirements is documented and agreed.
Questionnaires
Observations
Thought showers
Record searching/ document analysis
Fact recording
Unstructured findings

Business process modelling tools

Information flow diagram:

How how information moves between the parts of an organisation, internals and externally.

2 types of symbols internal and external

System flow chart:

Shows how data and information flows through the system, including manual operations and manipulation of information.

Systems pg 63 text book

Decision table
Defines the logic behind how a decision is made, this considers and document all possible outcomes.
Data flow diagram
Developed from system diagram, identifying where the data comes from, the processes it passes through and where the data goes to.

Data modelling tools
Entity attribute diagram- shows the relationship between an entity and the attributes that describe it.
Entity relationship diagram- shows how two or more entities are related. Symbols pg 66

Techniques for testing

• test harnesses- some types of testing to be automated via a framework that runs under specified conditions and monitors its outputs and processes.
• Volume testing- show how the system performs with different volumes of data
• Scalability- makes sure that the system will function correctly and give acceptable performance level when the system is scaled up to its full requirements.
• Prototyping- useful technique for gathering feedback from clients about the user interface and improving it following their comments.
• Multi-platform- run test on a variety of target platforms (windows, mac OS, Linux)
• use of simulated environments-simulate environments, testing how they might perform such as a clients WAN and can be repeated over and over again.