Dec 1998 SD206: Systems Design (Question 4)

(a)	List three major objective of system testing.	[3]
	One mark should be awarded for each valid point (up to a maximum of three marks). Examples include the following: To perform a final test of all programs against their specifications. To ensure that the operations group has adequate documentation and instructions to operate the system properly, process the incoming data, and distribute outgoing information from the system. To guarantee that the end users can successfully interact with the system. To test the backup and restart capabilities of the system to be sure that they are adequate under real processing conditions. To verify that all system components are correctly integrated so that data and information flow smoothly among departments and through the system within predicted time requirements. To confirm that the system can handle normal production volumes of data in a timely and responsive manner. Other sensible answer should also receive credit.
(b)	What sort of pressures might be exerted on a developer to finish testing earlier rather than later?	[2]
	One mark should be awarded for each valid point (up to a maximum of two marks). Examples include the following: If the project has fallen behind schedule. If the cost of the project has exceeded expectations. Other sensible answer should also receive credit.
(c)	List three things which may be verified in a post-implementation evaluation.	[3]
	One mark should be awarded for each valid point (up to a maximum of three marks). Examples include the following: That the new system meets its requirements. That the new system complies with end user objectives. That the new system achieves anticipated benefits. Other sensible answer should also receive credit.
(d)	Give two reasons why a project might not be subjected to a post-implementation review.	[2]
	One mark should be awarded for each valid point (up to a maximum of two marks). Examples include the following: The end users are keen to get on with their work. The system personnel must be reassigned to new projects. No qualified individuals are available to conduct the evaluation. The management don’t appreciate the potential benefits of such a review. Other sensible answer should also receive credit.
(e)	A company has decided to convert from an old computer system to a new one using modular conversion. Describe this technique.	[2]
	Modular conversion is associated with the implementation of a new system on a piecemeal basis (1 mark). As an example, an inventory system might be initially converted according to products or locations (1 mark). Other sensible answer should also receive credit.
(f)	Give three advantages of the modular conversion approach.	[3]
	One mark should be awarded for each valid point (up to a maximum of three marks). Examples include the following: The risk of a system’s failure is localised. The problems identified in the system can be corrected before further implementation is attempted. Other operating personnel can be trained in a ‘live’ environment before the system is implemented at their location. Other sensible answer should also receive credit.
(g)	Describe one way of increasing the reliability of a new system.	[2]
	One mark should be awarded for each valid point and a further mark should be awarded for a satisfactory elaboration (up to a maximum of two marks). Examples include the following: Error avoidance (1 mark). This involves making every possible attempt to prevent errors from occurring at all (1 mark). Error detection and correction (1 mark). This involves detecting errors and making necessary changes to correct either the error or its effect, so that a failure does not occur (1 mark). Error tolerance (1 mark). This involves keeping the system running, even in the presence of errors (1 mark).
(h)	Give three ways of reducing the need for maintenance for a new system.	[2]
	One mark should be awarded for each valid point (up to a maximum of three marks). Examples include the following: Define more accurately the user’s requirements during system development. Assemble better system documentation. Use more effective methods for designing processing logic and communicating it to project team members. Make better use of existing tools and techniques. Manage the systems engineering process effectively. Other sensible answer should also receive credit.