Worksheet »

 

1. Option 4 (corrective maintenance is about correcting errors in the implementation of a system, whilst adaptive maintenance is about adjusting a system to meet new or change user requirements)

2. Answer 3

3. Answer 4: a system model does not have to represent every aspect of a system- sometimes we deliberately omit detail in order to focus on a specific aspect of a description

4. Abstraction is the concept of focusing on specific detail and omitting other detail in order to aid clarity.  To abstract is to 'take away from', thus reducing detail to make what remains more clear.

5. Answer 5 is correct.  The remaining answers are wrong for the following reasons:

   1. Structured analysis and design seeks to develop a series of autonomous modules which can act independently. No- this is what object oriented analysis and design does; the structured approach seeks to establish a control hierarchy.

   2. Object oriented analysis and design is about establishing a hierarchy of control.  No, this is what the structured approach does.

   3. Structured analysis and design and object oriented analysis and design use different techniques, but ultimately result in the same system design and implementation.  No, they lead to different designs, software architectures and systems.

   4. Object oriented analysis and design was developed and more widely used before structured analysis and design.  The object oriented approach dates back to 1967, but was not widely used.  It is only in recent years that the object approach has gained popularity over the structured approach.

6. A system Specification presents an implementation-independent description of the system which can be reused for a number of designs