Sample Outlines for SRS Organization


_______________________________________________________________________________

IEEE/ANSI 830-1998  (after Sommerville and Davis)

1.  Introduction
    1.1  Purpose of the requirements document
    1.2  Scope of the product
    1.3  Definitions, acronyms and abbreviations
    1.4  References
    1.5  Overview of the remainder of the document

2.  General description
    2.1  Product perspective
    2.2  Product functions
    2.3  User characteristics
    2.4  General constraints
    2.5  Assumptions and dependencies

3.  Specific requirements

    cover functional, non-functional and interface requirements.  This is
    obviously the most substantial part of the document but because of the
    wide variability in organizational practice, it is not appropriate to
    define a standard structure for this section.  The requirements may
    document external interfaces, describe system functionality and
    performance,  specify logical database requirements, design constraints,
    emergent system properties and quality charcteristics.  Some alternative
    formats are shown below.

4.  Appendices

5.  Index


		    Some alternatives for Section 3
	            -------------------------------
Alternative I:

3.  Specific requirements
    3.1  Functional requirements
	 3.1.1  Functional  requirement 1
		3.1.1.1  Introduction
		3.1.1.2  Inputs
		3.1.1.3  Processing
		3.1.1.4  Outputs
	 3.1.2  Functional requirement 2
	   :
	   :
	 3.1.n  Functional requirement n
	   :
	   :
    3.2  External interface requirements
	 3.2.1  User interfaces
	 3.2.2  Hardware interfaces
	 3.2.3  Software interfaces
	 3.2.4  Communications interfaces
    3.3  Performance requirements
    3.4  Design constraints
	 3.4.1  Standards compliance
	 3.4.2  Hardware limitations
	   :
	   :
    3.5  Attributes
	 3.5.1  Availability
	 3.5.2  Security
	 3.5.3  Maintainability
	 3.5.4  Transferability/conversion
	   :
	   :
    3.6  Other requirements
	 3.6.1  Data base
	 3.6.2  Operations
	 3.6.3  Site adaptation

	              -------------------------------
Alternative II:

3.  Specific requirements
    3.1  Functional requirements
	 3.1.1  Functional requirement 1
	 	3.1.1.1  Specification
			 3.1.1.1.1  Introduction
			 3.1.1.1.2  Inputs
			 3.1.1.1.3  Processing
			 3.1.1.1.4  Outputs
	 	3.1.1.2  External interfaces
			 3.1.1.2.1  User interfaces
			 3.1.1.2.2  Hardware interfaces
			 3.1.1.2.3  Software interfaces
			 3.1.1.2.4  Communication interfaces
	 3.1.2  Functional requirement 2
	   :
	   :
	 3.1.n  Functional requirement n
	   :
	   :
    3.2  Performance requirements
    3.3  Design constraints
    3.4  Attributes
	 3.4.1  Availability
	 3.4.2  Security
	 3.4.3  Maintainability
	 3.4.4  Transferability/conversion
	   :
	   :
    3.5  Other requirements
	 3.5.1  Data base
	 3.5.2  Operations
	 3.5.3  Site adaptation

	              -------------------------------
Alternative III:

3.  Specific requirements
    3.1  Functional requirements
	 3.1.1  Functional  requirement 1
		3.1.1.1  Introduction
		3.1.1.2  Inputs
		3.1.1.3  Processing
		3.1.1.4  Outputs
		3.1.1.5  Performance requirements
		3.1.1.6  Design constraints
			 3.1.1.6.1  Standards compliance
			 3.1.1.6.2  Hardware limitations
			     :
			     :
		3.1.1.7  Attributes
			 3.1.1.7.1  Availability
			 3.1.1.7.2  Security
			 3.1.1.7.3  Maintainability
			 3.1.1.7.4  Transferability/conversion
			     :
			     :
		3.1.1.8  Other requirements
			 3.1.1.8.1  Data base
			 3.1.1.8.2  Operations
			 3.1.1.8.3  Site adaptation
			     :
			     :
	 3.1.2  Functional requirement 2
	   :
	   :
	 3.1.n  Functional requirement n
	   :
	   :
    3.2  External interface requirements
	 3.2.1  User interfaces
		3.2.1.1  Performance requirements
		3.2.1.2  Design constraints
			 3.2.1.2.1  Standards compliance
			 3.2.1.2.2  Hardware limitations
			     :
			     :
		3.2.1.3  Attributes
			 3.2.1.3.1  Availability
			 3.2.1.3.2  Security
			 3.2.1.3.3  Maintainability
			 3.2.1.3.4  Transferability/conversion
			     :
			     :
		3.2.1.4  Other requirements
			 3.2.1.4.1  Data base
			 3.2.1.4.2  Operations
			 3.2.1.4.3  Site adaptation
			     :
			     :
	 3.2.2  Hardware interfaces
			     :
			     :
	 3.2.3  Software interfaces
			     :
			     :
	 3.2.4  Communications interfaces

	              -------------------------------
Alternative IV:

3.  Specific requirements
    3.1  Functional requirement 1
	 3.1.1  Introduction
	 3.1.2  Inputs
	 3.1.3  Processing
	 3.1.4  Outputs
	 3.1.5  External interfaces
		3.1.5.1  User interfaces
		3.1.5.2  Hardware interfaces
		3.1.5.3  Software interfaces
		3.1.5.4  Communications interfaces
	 3.1.6  Performance requirements
	 3.1.7  Design constraints
		3.1.7.1  Standards compliance
		3.1.7.2  Hardware limitations
		   :
		   :
	 3.1.8  Attributes
		3.1.8.1  Availability
		3.1.8.2  Security
		3.1.8.3  Maintainability
		3.1.8.4  Transferability/conversion
		   :
		   :
	 3.1.9  Other requirements
		3.1.9.1  Data base
		3.1.9.2  Operations
		3.1.9.3  Site adaptation
		   :
		   :
    3.2  Functional requirement 2
     :
     :
    3.n  Functional requirement n

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DoD DI-MCCR-80025A  (after Davis)

    Acronyms:

	CSCI  - Computer Software Configuration Item
	DI    - Data Item
	DID   - Data Item Description
	MCCR  - Mission Critical Computer Resources

1.  Scope
     1.1  Identification
     1.2  CSCI overview
     1.3  Document overview

2.  Applicable documents
     2.1  Government documents
     2.2  Non-Government documents

3.  Engineering requirements (for a CSCI)
     3.1  CSCI external interface requirements
     3.2  CSCI capability requirements
	  3.2.X  Capability X
     3.3  CSCI internal interfaces
     3.4  CSCI data element requirements
     3.5  Adaptation requirements
	  3.5.1  Installation-dependent data
	  3.5.2  Operational parameters
     3.6  Sizing and timing requirements
     3.7  Safety requirements
     3.8  Security requirements
     3.9  Design constraints
     3.10 Software quality factors
     3.11 Human performance/human engineering requirements
	  3.11.1  Human information processing
	  3.11.2  Forseeable human errors
	  3.11.3  Total system implication (e.g., training
		  support, operational environment)
     3.12 Requirements traceability

4.  Qualification requirements
     4.1  Methods (demonstrations vs. test vs. analysis vs. inspection)
     4.2  Special (e.g., facilities, formulae, tools)

5.  Preparation for delivery

6.  Notes (e.g., glossary, formula derivations, abbreviations,
    background information)

Appendices

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NASA SMAP-DID-P200-SW  (after Davis)

 1.  Introduction
 2.  Related documents
 3.  Requirements approach and tradeoffs
 4.  External interface requirements
 5.  Requirements specification
     5.1  Process and data requirements
     5.2  Performance and quality engineering requirements
     5.3  Safety requirements
     5.4  Security and privacy requirements
     5.5  Implementation constraints
     5.6  Site adaptation
     5.7  Design goals
 6.  Traceability
 7.  Partitioning for phased delivery
 8.  Abbreviations and acronyms
 9.  Glossary
10.  Notes
11.  Appendices

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NRL A-7E (adapted from Davis)

     Note:  This outline was for a complete reengineering of the flight
     control software for an existing, operational aircraft.  The new
     software was intended as a replacement for the old, to operate with
     the existing hardware.

     Acronyms:

	OFP  - Onboard Flight Program

 0.  Introduction
     0.1  Overview
     0.2  Notation
     0.3  Table formats
 1.  The TC-2 computer
     1.1  Purpose
     1.2  Data manipulation 
     1.3  Control transfer
     1.4  Interrupt system
     1.5  Input/output
 2.  Inputs and outputs (between OFP and environment)	__
     *  Acronym						  |
     *  Description					  | for
     *  Range, accuracy					  | each
     *  Format					  	  | item
     *  Instructions to read or transmit it		  |
     *  Comments					__|
 3.  Modes of OFP operation
     3.0  Introduction
     3.1  Legal mode combinations
     3.2  Alignment modes
     3.3  Navigation modes
     3.4  Transitions between modes
     3.6  Navigation update modes
     3.7  Test mode
 4.  Functions						__
     *  Which inputs and outputs			  | for
     *  Relationship of output to input			  | each
     *  Listed in relation to modes when appropriate	  | function
     *  Demand or periodic (i.e., what triggers it)	__|
 5.  Timing requirements				__
     *  For each function				  |
     *  Minimum and maximum limits			__|
 6.  Accuracy constraints on software functions
 7.  Undesired events					__
     *  All desired behaviors in response to such events  |
     *  Ordered by who/what detects the event		__|
 8.  Subsets						__
     *  Logical subsets of OFP for implementation	__|
 9.  Possible changes and enhancements
10.  Glossary of terms, abbreviations and acronyms in A7 community
11.  References (documents and people)
12.  Indices to data items, modes and functions
13.  Dictionary of terms used in specification


    This effort was much influenced by David Parnas as reflected, for
example, in the presence of sections 7, 8, and 9.  The outline also shows
a substantial effort to make the document useful for individuals not
(previously) involved with the A7, particularly sections 10 and 13.