Software requirement document is official statement of what the system developers should implement.

1. Topic
Interface specification
software requirement specification

2. Software requirement document

3. Definition
 Software requirement document is official
statement of what the system developers should
implement.
 It also called software requirement specifications or
SRS.
 It includes both user requirement and detailed
system requirement specifications.
• Software requirement document is official statement of
what the system developers should implement.
• It also called software requirement specifications or SRS.
• It includes both user requirement and detailed system
requirement specifications

4. Cont.…
Sometime user requirements and system requirement
are integrated on single description.
In other cases user requirements are define in an
introduction of system requirement specifications.
If requirement are large then system requirement
specifications are presented in separate document.
• Sometime user requirements and system requirement
are integrated on single description.
• In other cases user requirements are define in an
introduction of system requirement specifications.
• If requirement are large then system requirement
specifications are presented in separate document

5. Cont.
 Document requirement is essential when outside contactor is
developing the system.
 Agile development method argues that requirement rapidly
change so documents are out of date and large effort is
wasted.
• When the system will be developed by an external
contractor. Critical system specification need to be
precise and very detailed.
• Agile development method argues that requirement
rapidly change so documents are out of date and
large effort is wasted.
• E.g A number of organizations such a US
department of defense.

6. five steps are includes
Customer
system
managers
System
engineers
System teste
engineers
System
maintenance
engineers

7. steps
 System customer: specify the requirement and read them to
check that they meet their needs. Customer specify change
to the requirement .
 Managers: use the requirements document to plan a bid for
the system and to plan the system development process.
 System engineers : use the requirements to understand
what system to be developed.
System customer: specify the requirement and read
them to check that they meet their needs. Customer specify
change to the requirement .
Managers: use the requirements document to plan a bid
for the system and to plan the system development process.
System engineers : use the requirements to
understand what system to be developed.

8. Cont.
 System teste engineers: use the requirement to develop
validation tests for the system.
 System maintenance engineers : use the requirements to
understand the system and the relationship between its
parts. .
System teste engineers: use the requirement to develop
validation tests for the system.
System maintenance engineers : use the requirements
to understand the system and the relationship between its parts.
.

9. Interface specification
 Interface
 A inter face is a intersection between system and environment.
 Interface =system /environment
 Specification
 A Specification is a agreement
Between the produce of the services
Consumer of that services
Interface
A inter face is a intersection between system and environment.
Interface =system /environment
Specification
A Specification is a agreement
Between the produce of the services
Consumer of that services

10. Interface specification
 Large system era decomposed into a subsystem with well-defined interface
between these sub system.
 Three types of interface specification
 Procedural interface
 Data structures
 Data representation
• Large system are decomposed into a subsystem
with well-defined interface between these sub
system.
Four types of interface specification
1) Procedural interface
2) Data structures
3) Data representation
4) Message passing interface

11. Procedural interface
 Procedural interface
 Is used for calling the existing programs by the new programs.
 These interface are sometime called application programing interface
 (APLs)
 Procedural interface
 Provide data passnig from one sub system to another system.
Procedural interface
Is used for calling the existing programs by the new programs.
These interface are sometime called application programing
interface
(APLs)
Procedural interface
Provide data passing from one sub system to another system.

12. Data representation
 Data representation
 Ordering of the bits to match with the existing system
 Most common in real time and embedded system.
 Message passing interface
 Sub system requesting service from other sub systems
Data representation
Ordering of the bits to match with the existing system
Most common in real time and embedded system.
Message passing interface
Sub system requesting service from other sub systems

13. Thanks