Topic 9- System Development Life Cycle

Question 0

Describe direct changeover

Answer 0

1. Direct changeover could be used where they stop using the old system one day and start using the new system the next. An advantage of this is that it requires fewer resources e.g people money and equipment and that it is relatively simple providing nothing goes wrong but a disadvantage is that there is an element of risk especially if hardware and software are cutting edge because if the system fails then it could be disastrous to be business

Question 1

Describe using suitable examples some of the different types of maintenance that might have to be undertaken

Answer 1

1. During corrective maintenance bugs, which were not identified during the testing process, may become apparent when the system is operating in a live environment
2. During perfective maintenance security issues e.g. A virus threat may be detected which means that the system requires an extra level of protection
3. Adaptive maintenance may find changes in the business environment e.g a change in legalisation which may mean that the software is required to perform tasks it wasn’t originally designed for

Question 2

Describe parallel changeover

Answer 2

2. Parallel changeover is where the old ICT system is run alongside the nee ICT system for a period of time until all of the people involved with the new system are happy it’s working correctly. An advantage of this is that it is used to minimise the risk in introducing a new ICT system but then the new system is eventually abandoned and all of the work is done on the new system. A disadvantage is that there is a lot of unnecessary work which is expensive in people’s time.

Question 3

Why might users become dissatisfied with a system over time

Answer 3

1. The full range of requirements may not have been met or it may not supply users with the information they require, not living up to their expectations
2. The network performance or speed of access may become unacceptable as more users are added to the system
3. There may be too much time spent on updating the system
4. There may be comparability issues with newer versions of software

Question 4

Describe two different ways a system analyst could gather information about the existing system

Answer 4

1. Ask users of the system to fill in a questionnaire which is a quick method of gathering information about certain areas and no time needs to be wasted speaking to people. However people may forget to fill them in and the answers they get back may be very brief.
2. Can carry out interviews with management to see how they want the new system to work and what information they want included however this is very time consuming and a lot of people will have to be contacted

Question 5

What is a feasibility report?

Answer 5

The summary of an initial investigation to look at the likelihood of being able to create a new system with stated aims and objectives at a reasonable cost. The document is used by senior managers to asses whether it is worth continuing with the project

Question 6

What should a feasibility report include?

Answer 6

• aims and objectives (user requirements)
• details of current hardware/software and whether they have equipment and staff to implement new system
• Definition of the scope of the present system so that everyone is clear what the system does and what it doesn’t do in order to determine size and complexity of the proposed project
• major data processing functions and processes
• identification of problems with current system with a view to building a new system capable of fixing these problems
• analysis of costs and benefits of new system e.g. Staff, equipment, hardware, software, licences, communication systems, training etc. these will have to be weighed up against the benefits of the new system such as fewer errors, more management information, ability to complete translations in less time, increase in business owing to greater customer satisfaction