December 1999
SE203 : SOFTWARE ENGINEERING

QUESTION 2

Total Marks: 15 Marks

• Question 1
• Question 3
• Question 4
• Question 5
• Cover Page

SUGGESTED SOLUTIONS
Solutions and allocated marks are indicated in green.
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The following statements have been made in relation to software demand:

(i)software demand increased with the use of personal computers

(ii)software demand increased with the use of microprocessors in intelligent products

Based on your understanding of software demand,discuss in some detail each of the two statements.Explain the extent to which you agree with them,or not.
As this part of the question is quite open,marks should be allocated for each sub-part as follows:

•0marks if candidate demonstrates no understanding of material,or fails to explain the question statement at all

•1 mark if the candidate succeeds,at a superficial level,to explain the trend

•2 marks if candidate clearly has sound understanding,and provides a clear explanation the trend,with a clear relation to the statement

The use of fourth-generation languages (4GLs)can make a signi .cant impact upon development methods and techniques.

(i)What are the important characteristics of a fourth-generation language,or a fourth-generation technique?[2 marks ]
The use of a high-level description language (1 mark),close to natural language (1 mark),code is generated automatically from the high-level language (1 mark). One mark for each of the points,or alternative correct answers,to a maximum of two marks .

(ii)With the aid of a diagram,explain how 4GLs (or 4GTs)can be used in different steps of the software development process.
Candidates should draw a process diagram with at least four steps:
•requirements gathering
•design strategy
•implementation using 4GL
•product

(1 mark)Award one mark for a diagram with these four steps —separating steps more finely,for example,splitting product into testing and maintenance is okay but award no extra marks —alternative,sensible labels are also acceptable 4GLs may be used to construct prototypes for use in the requirements gathering stage.(1 mark)Award an extra mark if the candidate supplies a correct diagram to illustrate this point,as on Page 1-9 of the study guide,to a maximum of four marks for this part of the question. Non-procedural 4GLs may be used to simplify the design step,moving straight from requirements gathering to implementation.(1 mark)This is more suitable for smaller systems.(1 mark)
The results of the design stage can be expressed in a 4GL,and parts of the software product can be generated automatically =code generation.(1 mark).

Explain what is meant by requirements analysis .
Sequirements analysis is the process of discovering,refining,modelling and specifying in a software project.2 marks for this,1 mark for a weaker but substantially correct definition

What are the three main objectives of requirements analysis?
To specify software function and performance.
To indicate software interface with other systems.
To establish design constraints that the software must meet.One mark for each.