metrics used for specifying non-functional requirements

• Time
• Transactions / sec
• Response time
• Time to complete an operation
• Space
• Main memory
• Auxiliary memory
• (Cache)
• Usability
• Training time
• Number of choices
• Mouse clicks
• Reliability
• Mean time to failure
• Downtime probability
• Failure rate
• Availability
• Robustness
• Time to recovery
• % of incidents leading to catastrophic failures
• Data corruption probability after a failure

template of IEEE standard SRS document

Software Document

 Should provide for communication among team members

Use the requirements todevelop validation tests forthe systemUse the requirementsdocument to plan a bid forthe system and to plan thesystem development processUse the requirements tounderstand what system is tobe developedSystem testengineersManagersSystem engineersSpecify the requirements andread them to check that theymeet their needs. Theyspecify changes to therequirementsSystem customersUse the requirements to helpunderstand the system andthe relationships between

 Should act as an information repository to be used by maintenance engineers

 Should provide enough information to management to allow them to perform all program management related activities

 Should describe to users how to operate and administer the system

 Specify external system behaviour

 Specify implementation constraints

 Easy to change

 Serve as reference tool for maintenance

 Record forethought about the life cycle of the system i.e. predict changes

 Characterise responses to unexpected events

IEEE Standard SRS Template

1. Introduction

    1.1.       Purpose

    1.2.       Scope   

    1.3.       Definitions, acronyms & abbreviations

    1.4.       References

    1.5.       Overview

2. Overall description

    2.1.       Product perspective

         2.1.1. System interfaces

         2.1.2. User interfaces

         2.1.3. Hardware interfaces

         2.1.4. Software interfaces

         2.1.5. Communications interfaces

2.1.6. Memory constraints

         2.1.7. Operations

         2.1.8. Site adaptation requirements

    2.2.      Product functions

    2.3.      User characteristics

    2.4.      Constraints

    2.5.      Assumptions and dependencies

    2.6.      Apportioning of requirements

3. Specific Requirements

3.1 External interface requirements

3.1.1 User interfaces

3.1.2 Hardware interfaces 

3.1.3 Software interfaces  

3.1.4 Communication interfaces 

3.2 Specific requirements

3.2.1 Sequence diagrams

3.2.2 Classes for classification of specific requirements

3.3 Performance requirements

3.4 Design constraints

3.5 Software system attributes

3.5.1 Reliability

3.5.2 Availability

3.5.3 Security

3.5.4 Maintainability

3.6 Other requirements

4. Supporting information

4.1 Table of contents and index

4.2 Appendixes

.