The System Engineering is an information system that involves human, software and hardware elements. This is the first stage of an information system’s project to recognize the major needs for the whole system and then to recognize those parts of the system that are the fines implemented in its software. This phase produces a high-level arrangement that defines how the main parts of the system will cooperate with each other. Requirements Analysis A Requirements Analysis is a description of the behaviour of the system that is to be developed.
All the systems requirements need to be defined clearly. It includes a set of functional requirements that describes all the interactions the users will have with the software. If the project is worried with the development of elements that will be implemented in the software then these are the main focus of the requirements analysis. Design Once the system knows what they want from it, the design process can precede in problem solving and planning for the system.
The design stage involves in getting a steadiness between requirements that conflict with each other, for example; maintainability and performance within the system. Construction The design phase is translated into the programme code. The structure may make use of different programming languages and database management systems for dissimilar parts of the system. Testing The system is tested to make sure that it satisfies the user’s needs perfectly and completely. Many levels of testing are performed.
Individual mechanism are tested alone then are tested together as a sub system and then the sub systems are tested jointly as a complete system. Installation Once the system has been tested satisfactory it is delivered to the customer and installed for use. The introduction of the system has to be managed carefully so as not to cause unnecessary distribution and to minimize the attendant risk of change. For example, the approach is to run both the old and new systems in parallel to ensure that the new system operates effectively before discontinuing the operation of the old system.
Maintenance It is most likely that the system will be a topic to change throughout its operating life. The delivered system may have received some corrections, and definite aspects of the system’s performance may not have been entirely implemented because of price or time constraints, but are then finished during this phase the maintenance. Adjusting scope during the life cycle can kill a project Easy to manage due to the rigidity of the model, each phase has specific deliverables and a review process
No working software is produced until late during the life cycle Phases are processed and completed one at a time High amounts of risk and uncertainty Works well for smaller projects where the requirements are understood well The life cycle model is sequential. The project phase overlaps and activities may have to be repeated Specialized teams may carry out the particular stages in the Life Cycle Iterations between the different phases in the life cycle are inevitable.
The requirements analysis may become evident during design, implementation or testing The progress of the project can be evaluated at the end of each phase and the decision to proceed to the next phase is decided at the end of the phase A great deal of time may elapse between the initial start up of the project and the final installation. The requirements may have been changed and hamper the organisation’s current operations The controlled approach can reduce the risks on especially large projects.