SOFTWARE SYSTEM ANALYSIS
System analysis is the development step that comes after study. As per the study conducted over the existing system a more detail study is conducted and feasibility of the system is examined. The study is carried out with a view making the system more effective by modifications or by substantial redesign. The system is analyzed by gathering various information like:
- How the system functions currently?
- What are the problems encountered?
- What are the requirements for the proposed system?
- Who the users are?
- What are their tasks and responsibilities?
1. Problem Analysis
Problem analysis is an important aspect of system analysis process. By problem analysis we mean how the existing system performing, the problem facing with the existing system, requirement specification and an overall concept of the proposed system.
The concept of proposed system is clearly defined above for submitting before the user for later suggestions and requirements. These requirements will be considered with the defined proposed system during the designing of the system.
2. Requirement Analysis
Requirement analysis bridges the gap between the system engineering and software design. A requirement is a feature that must be included in the new system. Requirement analysis enables the system engineer to specify the functions and performance, indicates the software interface with other system elements and establish design constraints that the software must meet.
External Interface Requirements
User Interfaces
After the user logs in he/she will be provided with a standard screen layout that is maintained throughout his session. This includes a standard header, a dynamic menu that is built according to the Objects that he/she has access to.
Software Interfaces
The application is developed using ASP.NET VBcode behind and SQL Server 2005 as back end.
Other Non Functional Requirements
Performance Requirements
Performance will be a key consideration while designing the software. The application will be scalable and robust and will provide steady performance.
Safety Requirements
Since this application will handle sensitive data we are using Http protocol to transfer the data in order to assure its safety.
Software Quality Attributes
Since this is a web application it will be developed keeping in mind that it will follow all major Web standards currently in use, including CSS2, HTML4, HTTP1.1, Java Script and Unicode. The software will be tested in all the major web browsers like Internet Explorer 5 and above, and Mozilla
Design Constraints
Design constraints refer to the software and hardware required to implement the proposed system.
1. Software Constraints:-
The server software is to run under the operating system Windows NT in the server system and Windows XP in the client system. The software is coded in Visual Basic with SQL Server as backend.
2. Hardware Constraints
This project is web based one. Therefore should be enough network connection. And also these networks should be connected. To install the proposed system there should be Intel Pentium IV Processor 3.20 GHz, 512K / 800MHz FSB, 40 GB Hard disk and 128MB (min) RAM are enough for the system. The system should have devices such as keyboard, mouse, CD drive, Floppy drive etc.
3. Modeling
At technical level, software engineering begins with a series of modeling tasks that lead to complete specification of requirements and a comprehensive design representation for the software to be built. The analysis model, actually a set of models is the technical representation of a system. Most important methods proposed for analysis modeling are structured analysis and object-oriented analysis. In structured analysis we create models that depict information contents and flow. We partition the system functionally and behaviorally and we depict the essence of what must be built. This method release on data modeling to create a basis for a comprehensive mode. At the core of the analysis model lays the Data Flow Diagram(DFD).
3.1 Data Flow Diagram
DFDs are commonly used during problem analysis. A DFD shows the flow of data through a system. Data Flow Diagram is the central tool and the basis from which other components are developed. It shows the movements of data through the different transformations or process in the system.
Named Circle or bubbles shows the process and data flows are represented by named arrows entering or leaving the bubbles. Rectangle represents a source or sink, and is a net originator or consumer of data. In the data store, a process stores data in the system. The data store may represent computerized or non computerized devices. DFD can be hierarchically organized which help in portioning and analyzing large systems. Such DFDs together are called leveled DFD set. A leveled DFD has a starting DFD, which is very abstract representation of the system, identifying the major inputs and the outputs and the major processes in the system. Then each process is refined and a DFD is drawn for the process.
3.2 Data Dictionary
A data dictionary is a set of
§ Identification such as a data element name.
§ A clear data element definition.
§ One or more representation terms.
§ Optional enumerated values Code (
Within the context of a DBMS, a data dictionary is a read-only set of tables and views. Amongst other things, a data dictionary holds the following information:
§ Precise definition of data elements
§ User names, roles and privileges
§ Schema objects
§ Integrity constraints
§ Stored procedures and triggers
§ General database structure
§ Space allocations
One benefit of a well-prepared data dictionary is a consistency between data items across different tables. When an organization builds an enterprise-wide data dictionary, it may include both semantics and representational definitions for data elements. The semantic components focus on creating precise meaning of data elements. Representation definitions include how data elements are stored in a computer structure such as an integer, string or date format. Data dictionaries are one step along a pathway of creating precise semantic definitions.
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