A Software requirements specification document basically describes the intended purpose and environment for software/application under development. It completely describes the yield, cost, nature of the software/application.
This post explains how a Software Requirements Specification document is prepared for a project/application. In this post, I have taken airline database project as an example to explain few points with example. There are certain guidelines to be followed while preparing the software requirement specification document (more often, used as SRS Document/Report). You need to include purpose of your project, scope of the project, environment where your project will be run, hardware required for the project, software required to run or implement the project, safety and security requirements, software quality attributes of the project etc. This SRS document has been written using standard guidelines.
Table of Contents
1.2 Document Conventions
1.3 Intended Audience and Reading Suggestions
1.4 Project Scope
2. Overall Description
2.1 Product Perspective
2.2 Product Features
2.3 User Classes and Characteristics
2.4 Operating Environment
2.5 Design and Implementation Constraints
2.6 Assumptions and Dependencies
3. System Features
4. External Interface Requirements
4.1 User Interfaces
4.2 Hardware Interfaces
4.3 Software Interfaces
4.4 Communications Interfaces
5. Other Nonfunctional Requirements
5.1 Performance Requirements
5.2 Safety Requirements
5.3 Security Requirements
5.4 Software Quality Attributes
The purpose of this document is to provide the software requirement specification report for the airline database.
1.2 DOCUMENT CONVENTIONS
|DDB||Distributed Data base|
1.3 INTENDED AUDIENCE AND READING SUGGESTIONS
This project is the college level project and is implementing under the guidance of college professors. This project is useful to everyone who travels in flights.
1.4 PROJECT SCOPE
The purpose of the online system is to create convenient and easy-to-use online system for passengers, trying to buy airline tickets. The system is based on a relational database with its flight management and reservation functions. We will have a database supporting dozens of major cities around the world as well as hundreds of flights by various airline companies. Above all, we hope to provide a comfortable user experience along with the best pricing available.
- fundamental of database systems by ramez elmarsi and shamkant b.navathe
2. OVERALL DESCRIPTION
2.1 PRODUCT PERSPECTIVE
A distributed Airline database System stores the following information as shown below .
- THEFLIGHT DETAILS:
It includes the originating flight terminal and destination terminal, along with stops in between, number of seats booked/available seats between two destination etc.
- CUSTOMER DESCRIPTION:
It includes customer code, name, address and phone number. This information may be used for keeping the records of customer for any emergency or for any other kind of information.
- RESERVATION DESCRIPTION:
It includes customer code number, flight number, date of booking, date of traveling .
2.2 PRODUCT FEATURES
The major features of airline data base system as shown in below entity–relationship model (ER model)
2.3 USER CLASS AND CHARACTERISTICS
Users of the system should be able to retrieve flight information between two given cities with the given dates/times of travel from the database. A route from city A to city B is a sequence of connecting flights from A to B such that: a) there are at most two connecting stops, excluding the starting city and destination city of the trip, b) the connecting time is between one to two hours. The system will support two types of user privileges, Customer and Employee. Customers will have access to customer functions, and the employees will have access to both customer and flight management functions. The customer should be able to do the following functions:
- Make a new reservation
o Flexible Date/time
- Cancel an existing reservation
- View his itinerary
The Employee should have following management functionalities:
- CUSTOMER FUNCTIONS.
o Get all customers who have seats reserved on a given flight.
o Get all flights for a given airport.
o View flight schedule.
o Get all flights whose arrival and departure times are on time/delayed.
o Calculate total sales for a given flight.
o Add/Delete a flight
o Add a new airport
o Update fare for flights.
o Add a new flight leg instance.
o Update departure/arrival times for flight leg instances.
Each flight has a limited number of available seats. There are number of flights that go from/to different cities at different dates and time.
2.4 OPERATING ENVIRONMENT
Operating environment for the AIRLINE DATABASE is as listed below
- distributed database
- client/server system
- operating system : windows xp.
- database: sql+ database
- platform: vb.net
2.5 DESIGN AND IMPLEMENTATION CONSTRAINTS
i) The global schema, fragmentation schema, allocation schema.
ii) SQL commands for above queries/applications
iii) How the response for application 1 and 2 will be generated. Assuming these are global queries. Explain how various fragments will be combined to do so.
iv) Implement the database at least using a centralized database management system.
2.6 ASSUMPTION DEPENDENCIES
Let us assume that this is a distributed airline database system and it is used in the following application:
- A request for booking/cancellation of flight from any source to any destination, giving connected flights in case no direct flight between the specified Source-Destination pair exist.
- Calculation of high fliers (most frequent fliers) and calculating appropriate
reward points for these fliers.
Assuming both the transactions are single transactions, we have designed a distributed
database that is geographically dispersed at four cities Delhi, Mumbai, Chennai and Kolkatta as shown in fig.2 above.
3. SYSTEM FEATURES
- DESCRIPTION AND PRIORITY
The airline reservation system maintains information on flights, classes of seats, personal preferences, prices and bookings.
Of course this project has high priority because it is very difficult to travel across countries without flights.
- STIMULUS/RESPONSE SEQUENCES
- Search for Airline Flights for two Travel cities
- Displays a detailed list of available flights and make a “Reservation” or Book a ticket on a particular flight.
- Cancel an existing Reservation.
- FUNCTIONAL REQUIREMENTS
- DISTRIBUTED DATABASE :
Distributed database implies that a single application should be able to operate transparently on data that is spread across a variety of different databases and connected by a communication network as shown in below figure.
- CLIENT/SERVER SYSTEM
A client/server system is a distributed system in which,
(a) some sites are client sites and others are serer sites.
(b) all data resides at the server sites.
(c) all applications execute at the client sites.
The term client/server refers primarily to an architecture, or logical division of responsibilities , the client is the application (also known as the front-end), and the server is the DBMS (also known as the back-end).
4. EXTERNAL INTERFACE REQUIREMENTS
4.1 USER INTERFACES
- Front-end software: Vb.net version
- Back-end software: SQL+
4.2 HARDWARE INTERFACES
- Windows XP.
4.3 SOFTWARE INTERFACES
|Operating system||We have chosen Windows XP operating system for its best support.|
|Database||To save the flight records, passengers records we have chosen SQL+ database.|
|VB.Net||To implement the project we have chosen Vb.Net language for its more interactive support.|
4.4 COMMUNICATION INTERFACES
This project supports all types of web browsers.
We are using simple electronic forms for the reservation forms, ticket booking etc.
5. OTHER NONFUNCTIONAL REQUIREMENTS
5.1 PERFORMANCE REQUIREMENTS
The steps involved to perform the implementation of airline data base are as listed below.
E-R Diagram constitute a technique for representing the logical structure of a database in a pictorial manner. This analysis is then used to organize data as a relation, normalizing relation and finally obtaining a relation database.
ENTITIES : Which specify distinct real-world items in an application.
PROPERTIES/ATTRIBUTES : Which specify properties of an entity and relationships.
RELATIONSHIPS : Which connect entities and represent meaningful dependencies between them.
B) NORMALIZATION :
The basic objective of normalization is to be reduce redundancy which means that information is to be stored only once. Storing information several times leads to wastage of storage space and increase in the total size of the data stored.
If a Database is not properly designed it can gives rise to modification anomalies. Modification anomalies arise when data is added to, changed or deleted from a database table. Similarly, in traditional databases as well as improperly designed relational databases, data redundancy can be a problem. These can be eliminated by normalizing a database.
Normalization is the process of breaking down a table into smaller tables. So that each table deals with a single theme. There are three different kinds of modifications of anomalies and formulated the first, second and third normal forms (3NF) is considered sufficient for most practical purposes. It should be considered only after a thorough analysis and complete understanding of its implications.
5.2 SAFETY REQUIREMENTS
If there is extensive damage to a wide portion of the database due to catastrophic failure, such as a disk crash, the recovery method restores a past copy of the database that was backed up to archival storage (typically tape) and reconstructs a more current state by reapplying or redoing the operations of committed transactions from the backed up log, up to the time of failure.
5.3 SECURITY REQUIREMENTS
Security systems need database storage just like many other applications. However, the special requirements of the security market mean that vendors must choose their database partner carefully.
5.4 SOFTWARE QUALITY ATTRIBUTES
- AVAILABILITY: The flight should be available on the specified date and specified time as many customers are doing advance reservations.
- CORRECTNESS: The flight should reach start from correct start terminal and should reach correct destination.
- MAINTAINABILITY: The administrators and flight in chargers should maintain correct schedules of flights.
- USABILITY: The flight schedules should satisfy maximum number of customers needs.