Section 11.3
System Development
11.3 Design
In designing a new system all aspects of the design must be documented.
This involves:
- designing screen layouts and reports formats.
- specifying file contents and organisation.
11.3.2 Prototyping
This is an aid to better, faster, systems design.
In a computing context, prototyping involves building a simple model of software under
development.
This could involve using special software to quickly design input screens and validate
data input.
This gives the user a chance to experience the look and feel of the input process.
Note that prototyping would also be used during analysis.
11.3.3 Computer Aided Software Engineering (CASE)
These are software tools that insist in the design or development of a system.
Examples of CASE software:
- Graphics Tools - to draw structure diagrams, data flow diagrams,
etc.
- Interface Generator - for rapid prototyping.
- Project Management Tools - schedule the steps in analysis, design,
coding and testing.
11.3.4 Design Choices
Firstly decide upon:
Processing Method
The systems designer will need to chose between Batch Processing and On-Line Processing.
This decision will be dependant on:
- how often the data changes.
- the volume of data.
- the cost of hardware.
- how the data is collected.
Software Solution
In general there will be many different solutions to a problem.
The following affect this choice:
- Usability
- Performance
- Suitability
- Maintenance
Hardware Solution
This depends on many factors, for example:
- The software
- Volume of data
- Number of users and their locations
- Processing method
- Security considerations
