3.4.3 STAGES IN WATERFALL MODEL
Requirement analysis
This is the initial phase of the waterfall model, an analysis is done on the existing system and the requirement of the new system are to be identified. All the requirements for the new system are gathered employing techniques such as interview and observation. All information gathered will be analyze. The functional and non-functional requirement of the new system will be engineered and scope of the development efforts will be determined. Developers will understand what the proposed system means in the technical way and how it will be incorporated into the existing system. All possible requirements of the system to be developed are captured in this phase and documented in a requirement specification document.
System design
The third phase of SDLC is called system design. During system design, analysts convert the description of the recommended alternative solution into logical and physical system specifications. You must design all aspects of the system from input and output screen to reports, databases, and computer processes. The dataflow diagram(DFD) will be used to link the whole system with the specification and provided detailed description regarding the flow of information between the tables. This is followed by the normalization method. All the tables will be created and normalized to minimize its dependency and redundancy. Primary and foreign keys in each will be identified to enhance the database. After identifying the normalized tables, a computer database for the system will be created. The database design will be equipped with detailed description of each attribute by field name, data type, and data validation and description. The requirement specifications from first phase are studied in this phase and the system design is prepared. This system design helps in specifying hardware and system requirements and helps in defining the overall system architecture.
System Development
This is the third phase where all the designs will be translated into machine-readable coding. The coding is done keeping in mind that there might be future enhancement and the system reliability.
System Testing
The fourth phase is testing the complete software based on the functional and non-functional requirements. Each components of the software will be tested separately to ensure an error free software and component integration. The testing activity includes information on the program, tested item, and expected action or value and remark criteria. Brings all the pieces together into a special testing environment, then checks for errors, bugs and interoperability.
System implementation
The fifth phase which is the implementation process concentrates on how the developed system plan is to be implemented for members use and training the operating members before the software system is functional. The customer evaluates and provides feedback based on the evaluation carried out. With inputs from the system design, the system is first developed in small programs called units, which are integrated in the next phase. Each unit is developed and tested for its functionality, which is referred to as Unit Testing.
3.4.4 REASONS FOR CHOOSING WATERFALL MODEL
ï¶ It works well for smaller projects
ï¶ Waterfall model works well for smaller projects where requirements are very well understood.
ï¶ In this model phases are processed and completed one at a time. Phases do not overlap.
ï¶ This model is simple and easy to understand and use.
ï¶ Progress of system development is measurable.
