What is Requirement Analysis for Web Applications?

Requirement analysis for web applications consists of formulation, requirement gathering and analysis modeling.
- In formulation, goals and objectives and categories of users for web application are identified.
- In requirement gathering, communication between web engineering team and stakeholders deepens.
- In analysis modeling, content and functional requirements are listed and interaction scenarios are developed.

USER HIERARCHY
It is a good idea to build a user hierarchy. It provides you with a snapshot of user population and a cross check to help ensure that the needs of every user have been addressed. End-user categories interacting with web application are identified. As the number of user categories increases, developing a user hierarchy is advised. User categories provides an indication of functionality provided by WebApp and indicate need of use cases to be developed for each end-user in hierarchy.

DEVELOPING USE CASES
For each user category, use cases are developed which is described in user hierarchy. A use case is relatively informal i.e. a narrative paragraph that describes a specific interaction between user and web application. As the size of web application grows and analysis modeling becomes more rigorous, the preliminary use cases presented would have to be expanded to conform.

REFINING USE CASE MODEL
Use cases are organized into functional packages and each package is assessed to ensure that it is comprehensible, cohesive, loosely coupled and hierarchically shallow. The new use cases will be added to packages that have been defined, existing use cases will be refined and specific use cases might be reallocated to different packages.

Testing activities in Requirements Analysis phase

The following test activities should be performed during this stage :
- Invest in analysis at the beginning of the project.
Having a clear, concise and formal statement of the requirements facilitates programming, communication, error analysis and the test data generation. The requirements statement should record the following information and decisions :
+ Program function - what the program must do?
+ The form, format, data types and units for input.
+ The form, format, data types and units for output.
+ How exceptions, errors and deviations are to be handled?
+ For scientific computations, the numerical method or at least the required accuracy of the solution.
+ The hardware and software environment required or assumed.
Deciding the above issues is one of the activities related to testing that should be performed during this stage.

- Start developing the test set at the requirements analysis phase
Data should be generated which can be used to determine whether the requirements have been met. To do this, the input domain should be partitioned into classes of values that the program will treat in a similar manner and for each class a representative element should be included in the test data. In addition, following should also be included in the data set: boundary values, any non-extreme input values that would require special handling. The output domain should be treated similarly. Invalid input requires the same analysis as valid input.

- The correctness, consistency and completeness of the requirements should also be analyzed.
Consider whether the correct problem is being solved, check for conflicts and inconsistencies among the requirements and consider the possibility of missing cases.

Conceptual Data Models for Database Design

Conceptual modeling is an important phase in designing a successful database application. The database design process consists of a number of steps listed below:

Step 1: Requirements Collection and Analysis
- Prospective users are interviewed to understand and document data requirements
This step results in a concise set of user requirements, which should be detailed and complete.
- The functional requirements should be specified, as well as the data requirements. Functional requirements consist of user operations that will be applied to the database, including retrievals and updates.
- Functional requirements can be documented using diagrams such as sequence diagrams, data flow diagrams, scenarios, etc.



Step 2: Conceptual Design / Data Modeling
- Once the requirements are collected and analyzed, the designers go about creating the conceptual schema.
- Conceptual schema: concise description of data requirements of the users, and includes a detailed description of the entity types, relationships and constraints.
- The concepts do not include implementation details; therefore the end users easily understand them, and they can be used as a communication tool.
- The conceptual schema is used to ensure all user requirements are met, and they do not conflict.

Step 3: Database Design
- Two sub-steps called Database Logical Design which define a database in a data model of a specific DBMS and Database Physical Design which define the internal database storage structure are defined.
- It also defines file organization or indexing techniques.

Step 4: Database Implementation
- Many DBMS systems use an implementation data model, so the conceptual schema is transformed from the high-level data model into the implementation data model.
- This step is called logical design or data model mapping, which results in the implementation data model of the DBMS.

Step 5: Physical Design
- Internal storage structures, indexes, access paths and file organizations are specified.
- Application programs are designed and implemented.