SYSTEM LIFE CYCLE Theory
All of the information obtained through interviews, questionnaires, observations and paper trails is carefully examined and analysed to determine the requirements for the new IT system.
The findings are translated into a set of specific diagrams which represent how the system will work and the processes required.
The main diagrams are:
System diagrams |
These show the relationships between the various systems in the company (or even outside if relevant) - how they interact, what depends on what and so on. |
Data Flow Diagrams |
Most systems deal with information in one way or another. What really matters is how the information flows through the system. How does it branch and re-join. What outputs are created and so on. The 'data flow' diagram seeks to show this movement through the system. |
Process diagrams |
People handle information in a specific way - they have a 'process'. For example, an employee makes an expense claim. First of all their manager counter-signs the claim. It then goes to the account manager who authorises payment and so on...This is 'process flow' in action. Process diagrams try to show how people interact with the system - who and when (and why). |
Once the diagrams have been completed, two key documents/ reports are produced:
1. A full written analysis of the current system, the processes and the problem it causes
2. Detailed user requirements for the new system
These documents will be used by the system developers and so must be clearly written, broken down into relevant stages and contain all of the necessary details for them to create the new system. |
challenge see if you can find out one extra fact on this topic that we haven't already told you
Click on this link: Documenting system