Aug 1997 SA205: Systems Analysis (Question 5) Suggested Solutions

5.	(a) Why is the Preliminary Investigation phase considered to be a crucial stage in a system development project?		[2]
	The Preliminary Investigation phase is important because it is during this phase that projects are screened and only those that are approved are carried over to the next phase.
	[2 marks]

	(b) Describe the competitive advantage that a stock-monitoring computer system would provide to a supermarket.		[4]
	A stock-monitoring computer system would allow a supermarket to have a greater understanding of the number and the time of day that each product is purchased from the shop.		[1]
	Therefore, the supermarket could anticipate the consumers' desires with more accuracy and ensure that the shelves are stocked according to these predictions.		[2]
	Thereby reducing the opportunity that a customer wants a product that is not on a shelf, or having shelves full of products that the customers do not want.		[1]
	[4 marks]

	(c) Explain, with the aid of an example in each case, the factors to be considered in defining the scope and constraints of a system.		[6]
	The factors to be considered while defining the scope and constraints of the system:
		Present vs Future constraints.	[1]
		Any suitable example.	[1]
		Internal vs External constraints.	[1]
		Any suitable example.	[1]
		Mandatory vs Desirable constraints.	[1]
		Any suitable example.	[1]
	[6 marks]

	(d) A user may think that a system is needed to perform certain functions. However, further thought and analysis may identify additional or different functions that are required. Systems have diverse users with different needs and any set of requirements is inevitably a compromise.		[8]
	Show how the following four requirements could be rewritten to make them more precise, less ambiguous, and thus more easily validated.
	Any suitable improvement upon the four requirements will be acceptable; answers which are less precise, more confusing, or harder to establish, should be given no marks. Suitable examples include:
		1. If the system should fail in operation, there should be minimal loss of data.
		1. If the system should fail in operation, there should be no loss of data.
	[2 marks]
		2. The system interface should use a character set as available on a standard terminal.
		The system interface should use a character set as available on all computer systems (within reason). (Nowadays that might consist of Unicode)
	[2 marks]
		3. The software must be developed in such a way that it can be used by inexperienced users.
		3. The software must be developed in such a way that it can be used by novice and experienced users alike.
		[2 marks]
		4. All run-time errors should be caught.
		4. All run-time errors should be caught and handled properly so that the user is not left with a system prompt.
	[2 marks]