ICT A2

Analysis Stage

In this stage, as the name states, details into current system requiremnts and the requirements for a new system (if something similar hasn't been done before). The tools and techniques to be used for the system are determined in this stage and the predictions concerning the system i.e. delivary dates, errors and need for managment input, are also made in this stage.

 

Design Stage

This is the next stage after the analysis stage. In this stage the process of creating the solution is outlined in other to meet the client requirements. The system analyst will start to produce a design that would allow it to be built. Generally the design would be in-line with the user requirements and specify the needed software and hardware for the solution.

 

Build/Construction Stage

In this stage the system is built according to the design in the previous stage. The staff would be split into their areas of expertise to create a new working system. The construction would normally involve: Staff using physical design, Programming code writing, Customising software, Producing Framework for databases, Using software tools to produce the working and producing the working system according to user requirements.

 

The systems development life cycle is a process of stages which occur during the development of a new ICT system. Once a system is developed, it will need maintaining and eventually will be seen as inadequate to the users’ needs and so a new system will be needed.

 

Testing Stage

Testing is crucial when developing a system. The data used in testing should test that all aspects of the system perform as expected. The data should be used to test extreme and erroneous cases to ensure validation is working. Also when testing, the results produce should be compared with the expected results. If there are any errors, then they will be investigated and corrected.

There are different types of testing, which include:

• Module testing

  • This is where each part of the system is tested

• Functional testing (‘black-box’ testing)

  • Checks the outputs are correct for a given input

• System testing (‘alpha’ testing)

  • Developers test the system as a whole to make sure it meets its requirements

• User testing (‘beta’ testing)

  • Potential users will test the new software on their own computers using real data

• Operational testing

  • The software is tested in a normal operating environment

 

User testing (or ‘beta’ testing) is quite useful to test software before it goes on sale or is given to a company. In this instance the testers are users from outside the company who are given the software free of charge. This can be rewarding to the individual as they can use it before it is released to the general public.

 

 

Installation Stage

When the testing is complete and successful, the system can be implemented. At this stage in the systems life cycle, hardware must be purchased, the staff must be trained (if in a company), user documentation should be written and data files must be converted for the new system if necessary. There are 4 methods which can be used in this process:

 

 

• Direct changeover

  • This process involves completely removing the previously existing system and immediately replacing it with the new one. No time is wasted this way; however there is a big risk that something can go wrong. If it was possible, one of the other 3 methods should be used.

• Parallel running

  • In this instance, both the old and new system will be running together for a certain amount of time. When the new system is embedded and running smoothly, the old system is stopped. This method is safe, as a backup (the old system) is available just in case the new system encounters a problem. The only downside to this method is that it is costly as extra time is required.

• Phased conversion

  • This process involves a numerous amount of stages in which a changeover occurs. Therefore, this method is only appropriate for systems that can be broken down into separate sections that can be developed one after the other.

• Pilot conversion

  • In this case, the system is implemented in one department or location in advance of the whole organisation. This method is only possible in companies that have discrete sections or branches, and it may be necessary for the old system to run in parallel as well.

 

Review and maintenance

When the system is finally in full operation, it should be monitored to check that it has met the original requirements. The system will inevitably need changes, and these changes are known as systems maintenance (types of maintenance can be found here). More hours are spent on maintenance compared to the production of systems.

 

It is necessary to evaluate the success of the project and review its effectiveness. To do so, you have to look at the original requirements and testing/performance criteria to assess how well the requirements are being met during its lifetime. The evaluation will involve discussions between the management and users of the system to gather opinions of the new system.