The purpose of design phase is to plan a solution for problem specified by the requirements. System design aims is to identify the modules that should be in the system the specification of these modules and how they interact with each other to produce the desired result. The goal of the design process is to produce a module or representation of a system which can be used later to build that system. The produced model is called design of the system.
The most important phase of the software of the system is designing the different modules. The accurate planning and proper interconnections with the modules will give a good output in the implementation part.
Application documents :
As the project is user-friendly, it can be applied to large database with more information. This software can be used by Library Management System to make the work simple. They can get information quickly as possible. It can handle large volume of data and present the report whenever required. In this project, we use SRS as the applicable documents.
Function decomposition :
Functional decomposition refers broadly to the process of resolving the functional relationship into constituent parts in such a way that original function can be reconstructed (i.e. recomposed) from those parts by function composition. In general, this process of decomposition is undertaken either for the purpose of gaining insight into the identity of constituent components (which may reflect individual physical processes of interest, for example) or for the purpose of obtaining a compressed representation of global function, a task which is feasible only when the constituent processes possess a certain level of modularity (i.e. independence or non-interaction).
Functional component and assumption :
- Register user: New user can register.
- Book issue: Here the books will issue to the user.
- Book return: Here the books are returned.
- Search/view book details: It is used to search and view the books.
- Update book details: Here the details of the books will be updated.
- Payment: Here payment should be done in manual.
Description program :
Context Flow Diagram:
A Context Flow Diagram is 0th level DFD. It only contains one process node that generalizes the functions of the entire system in relationship to external entities. In Context Flow Diagram the entire system is treated as a single process and all its input, output sinks and source are identified and shown.
Data Flow Diagram:
A Data Flow Diagram is a graph showing the flow of data values from their source in objects through process that transform them to their destination in other objects.
DFD also knows as “Bubble charts” has the purpose of clarifying the system requirements and identifying major transformations that will become programs in system design. So it is the starting point of the design phase that functionally decomposes the requirements specifications down to the lowest level of details. A DFD consist s of a series of bubbles joined by lines.
DFD use a number of symbols to represent system. Most data flow modeling methods use 4 kinds of symbols to represent 4 kinds of system components: processes, data stores and external entities