Phase 3Phase 3The Software Requirements

Specification

The Software Requirements The Software Requirements SpecificationSpecification

After review of the customer’s System Spec.

After educated analysisPreliminary designA technical, software

“approach”Results in permission to detail-

design and code

Customer Points-of-Customer Points-of-ContentionContentionAssumptions, Constraints, LimitsFunctionDocumentation – technical, user,

and training manualsTrainingMaintenance / EnhancementsRequirements ChangesStatus and Reviews

From the customer’s From the customer’s perspectiveperspectiveHow smart people are going to

solve the problem that was stated in the System Spec.

A “contract”, more or lessIs it doable?

◦Technically◦On time◦Under budget

Settles these issues:Settles these issues:• Software Architecture

–Object Oriented?–Structured?–Database Oriented (Informational

Flow)?–Event Driven

• Major Modules–to 2 or 3 levels of supervision– low level utilities if they touch

hardware or the environment

Risk AssessmentRisk AssessmentTechnical Risks

◦ hardware / software / interfaces◦ build vs. buy◦ team expertise needed

Schedule Risks◦ budget◦ calendar◦ personnel – level of expertise required

Phase 3Phase 3Write PARTS OF an SRS

◦Architectural Drawings◦Main User Screen(s)◦Integration Thread (also a Drawing)◦Change of Scope Form◦Cross Reference Listing

What is a module?What is a module?

Outputs

Inputs

Storage

Processing

Simple Block Diagram FormArrows, of course, should be labeled

Data Flow DiagramData Flow Diagram

Data Conversion

DFD Standard ShapesArrows, of course, should be labeled

Temporary Storage

Sink

Source

Air TrafficControl

DisplayDatabaseRadar

Add Remove Edit

DiskAccess

DisplayRefresh

UI

Record Playback

SweepData

Conversion

DataInterpretation

City Simulator

Talking Head

Edit / Undo/ ReDo

User Interface Phrasing

Menu Presentation-Graphics, Text

Prediction

Phrase Completion

Build and Release

Rules Db

AudioConstruction

Synthesis Engine

MP3s

WAVsPresentation

Output

User Feedback

Logging,Monitoring, &Annunciation

Stored Menus

Phrase

Choice

Talker

CAPESensors

Operator(s)

ResultDatabase

Aircraft

Flight GuidanceData

Measurement ResultsMeasurement ResultsSensorData

SensorConfig

User IO

Data Flow Diagram - shows movement, conversion, and storage of data

This is the "top" drawing of a $6 million, 45-person, 1 million LOC, 4 year project

TCP/IP Stack(HTTP, SNMP,

Telnet)

Generation 2 Configuration Control Detail= Internal

Communication

Socket Input

File System

Serial Input

SerialTerminal

File Input Serial Input

CommandProcessor

Cloud Chart - (pre UML) object relationships