The System Investigation
When a new or upgraded system is introduced into an organisation, it is usually intended to support the work already carried out by the organisation. Although the new system may differ substantially from the existing system, the information being handled, and the main functions of the system, will remain relatively unchanged. An analysis of the existing system, therefore, provides a firm basis for the design of the new system.
Other reasons for performing a system investigation include:
- Determining the scope of the project, by evaluating the complexity of the problem and the effort required to complete it. This information can assist with planning the project and allocating the necessary resources to it.
- Increasing user confidence, by reassuring users that the analyst fully understands the nature of the problem, and the business operations that the system must carry out.
Some of the aspects that will be investigated include:
- Operations and data - an understanding of the current operations and data will make it easier to understand the requirements of the new system
- Existing problems - determining what the problems are with the existing system ensures that they will not be replicated in the new system
- System boundaries - determine which business areas are within the scope of the project, to ensure that effort is not wasted on areas that lie outside the scope of the project, and to ensure that all relevant areas are included. The system boundaries should be explicitly stated and agreed with all those concerned.
Note that an investigation of the existing system does not constrain the project team to simply re-hash the features of the current system. A fresh approach to meeting the system objectives is taken, and may lead to a complete restructuring of both the business processes and data, in a new system that is nothing like the old one.
Some investigation techniques:
- Studying the current system documentation
- Observation of the system in operation
- Reviewing previous studies
Some or all of these techniques may be used in the investigation of the existing system, and will result in a set of data flow diagrams representing the current system, a logical data structure of the current system's data, and the initial problems/requirements list for the project.