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Real-time Traffic Monitoring System SystemRequirements Review
Stevens Institute of TechnologySystems Engineering
SYS 625 Spring 2007
Team 1 Aaron Griggs ChristineAdelfio Louis Lovas Marvin Mondesir
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Table of Contents
Table of Contents ............................................................................... 2Need................................................................................................... 3Stakeholders ...................................................................................... 3Requirements ..................................................................................... 3
Drivers ..................................................................................... 3Passengers ............................................................................... 3Installers ................................................................................. 3Maintainers .............................................................................. 4Navigation System Manufacturers ............................................ 4Fleet Managers ......................................................................... 4Content Providers .................................................................... 4Emergency Responders ............................................................ 4
Acceptance Criteria ............................................................................ 5Concept Definition and Selection ........................................................ 5
Alternatives .............................................................................. 5Pugh Matrix .............................................................................. 5Selection and Rationale ............................................................ 5
Context Diagram (External Systems Diagram) ................................... 6Use Case Scenarios ............................................................................ 7Profile Management ................................................................. 7Hazardous Weather .................................................................. 8Traffic Jams.............................................................................. 9Maintenance and Diagnostic ................................................... 10Installation ............................................................................ 11
Quality Function Deployment ........................................................... 12Objective Hierarchy .......................................................................... 13System Requirements ...................................................................... 14
Functional Requirements ....................................................... 14Input Requirements.......................................................... 14Output Requirements........................................................ 14Interface Requirements ..................................................... 15
System-wide Requirements.................................................... 15Suitability Requirements ................................................... 15Physical Requirements ...................................................... 15Technology Requirements ................................................. 16Cost Requirements ........................................................... 16Standards and Protocols .................................................... 16Schedule Requirements by Phase ....................................... 16Supportability and Maintenance ......................................... 16
Functional Architecture .................................................................... 16Risks ................................................................................................ 18
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Need
People need to see and understand real-time traffic conditions. This opportunity provides driverswith recommended routes to avoid unsafe road conditions, whether it is weather related orcongestion from an accident. The end result: a more efficient commute and an overallhappier, safer driver.
Stakeholders
The following table represents the active and passive stakeholders (bold are the customers):
Active Passive
Drivers Navigation SystemManufacturers
Installers Fleet ManagersMaintainers Emergency Responders
Content Providers*
* Providers of weather, road conditions, routes data
Requirements
This section contains the requirements for all the identified stakeholders.
To gather requirements, interviews were conducted with drives. The goal was to understandhow drivers cope with unsafe road conditions, the factors that affect getting to destinationsgiven some standard conditions and some of their feelings as they drive under these conditions.
Note in a real environment, many interviews would be conducted with drivers in person and viathe Internet and phone. Sample of people would be taken from automobile membershiporganizations (i.e., AAA) or consumer panel survey participants.
Outcome is to determine whether the responses from interviewees justify the need for a real-time traffic condition notification system.
Drivers
Want a safe commute Want an efficient commute Want to understand why traffic is backed up Want alternative routes Want timely, accurate information on road conditions Want low (e.g. $20) monthly cost
Passengers Want a safe commute Want an efficient commute Want to understand why traffic is backed up
Installers
Easy to install
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Maintainers
Easy to repair
Navigation System Manufacturers
Easy to integrate Easy to update Cost effective Differentiates the navigation system
Fleet Managers Want efficient use of fleet vehicles Want to keep operators safe while on the road Lower insurance costs
Content Providers
Want to reach a larger audience
Emergency Responders
Want to detour traffic during accidents or hazardous road conditions Want timely, accurate information
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Acceptance Criteria
The following criteria were defined to influence the implementation of the system: Provide the driver with configurable, relevant up to date information. Easy and safe to use while driving. Reasonable monthly cost for basic service$10 per month.
Concept Definition and Selection
This section contains the alternative concepts, a Pugh Matrix to inform a single concept selectionand the selection with rationale.
Alternatives
Four concepts were defined: Radio Broadcast through radio air waves. Cell phone Audio and text service that is delivered through cellular networks. Traffic signs Text based digital traffic signs. Add-on service to existing navigation systems (e.g., Garmin, TomTom).
Pugh Matrix
Criteria Radio Cell phone Traffic Signs NavigationSystem
Ease of use S S S +
Configurability - S - +
Cost + S S S
Reliability S S - S
Timeliness - - - +
Safety S - + S
Integration S S S +Schedule + S S -
+ 2 0 1 4
- 1 2 3 1
S 4 6 4 3
Selection and Rationale
The Pugh Matrix shows the navigation system scoring slightly higher than the other concepts.Although the radio, cell phone and traffic sign solutions satisfy the criteria (evident by thescores), the navigation system is favored when weighing ease of use, accuracy andconfigurability. Given the goal for a better view into road and traffic conditions, the navigationsystem is clearly the choice.
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Context Diagram (External Systems Diagram)
Shown below is the external system diagram for the real-time traffic monitoring system.Displayed are all the active stakeholders and their interactions with the system .
Profile Management
Road Conditions
Weather ConditionsReal-time Traffic
Monitoring SystemDrivers
Profile Management
ContentProviders
Location
Maintainers
Installers
Alternative Route Traffic Conditions
Road Conditions
Service Requests Service Requests
InstallationAlerts
Modes
Configurations
LogUpdates
Configurations
Modes
LogUpdates
Service
Alerts
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Use Case Scenarios
The main flow use case scenarios are defined for the active stakeholders.
Profile Management
The profile management use case is shown below. The system manages the content providers
and drivers preferences through profiles.
DriverContent Provider Traffic Monitoring System
Consumer Profile Modify Request
Consumer Activation Request
Consumer Activation Response
Consumer Profile Modify Response
Provider Activation Request
Provider Activation Response
Consumer Termination Request
Consumer Termination Response
Provider Profile Modify Request
Provider Profile Modify Response
Provider Termination Request
Provider Termination Response
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Hazardous Weather
The hazardous weather use case is shown below. The system receives weather and roadcondition information from content providers. When road conditions affect the driver based onthe drivers location, the driver is notified. The driver then requests an alternative route toavoid the traffic jam.
DriverContent Provider Traffic Monitoring System
Weather Hazard Notification
Alternative Route Request
Weather Alert Notification
Acknowledgement
Road Conditions Notification
Acknowledgement
Location Notification
Acknowledgement
Alternative Route Response
Acknowledgement
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Traffic Jams
The traffic jams use case is shown below. The system receives traffic information from contentproviders. When traffic conditions affect the driver based on the drivers location, the driver isnotified. The driver then requests an alternative route to avoid the traffic jam.
DriverContent Provider Traffic Monitoring System
Traffic Jam Notification
Alternative Route Request
Traffic Alert Notification
Acknowledgement
Traffic Conditions Notification
Acknowledgement
Location Notification
Acknowledgement
Alternative Route Response
Acknowledgement
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Maintenance and Diagnostic
The maintenance and diagnostics use case is shown below. The system receives a servicerequest from a driver. The request is forwarded to the maintainers. The maintainers test andmodify the system in diagnostics mode returning the system to normal operation aftermaintenance completion.
Driver or
Content ProviderTraffic Monitoring System
Log Update Request
Diagnostics Mode Request
Diagnostics Mode Response
Acknowledgement
Maintainers
Self Test Request
Self Test Response
Configuration Change Request
Configuration Change Response
Service Request
Acknowledgement
Normal Mode Request
Service Alert
Acknowledgement
Normal Mode Response
Normal Operation Notification
Acknowledgement
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Installation
The installation use case is shown below. The system receives an installation request from adriver. The request is forwarded to the installers. The installers install and configure thesystem in installation mode returning the system to normal operation after installationcompletion.
Driver or
Content ProviderTraffic Monitoring System
Installation Request
Installers
Acknowledgement
Log Update Request
Installation Mode Request
Installation Mode Response
Acknowledgement
Self Test Request
Self Test Response
Configuration Change Request
Configuration Change Response
Installation Alert
Acknowledgement
Normal Operation Notification
Acknowledgement
Normal Mode Request
Normal Mode Response
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Quality Function Deployment
Ease of use Intuitive 4Installation 3
Repair 3
Integration with content 5
Configurability Differentiate vehicles 3
Large customer base 4
Customizable 3
Cost Low Monthly subscription 5
Reliability Minimal maintenance 4
Timeliness Road conditions 5
Traffic conditions 5
Weather conditions 5
Efficienct commute 4
Safety Less accidents 2
Reduce congestion 2
- ++
++
++ ++
+ + +
+ +
+++
+++ ++ ++
++ +++++
+++ ++ ++
+++ + + +++++ +++ +++ ++
+++
+++
++
+++
+++ +++
++ ++++ ++ ++++++
++ +++++++ +++ ++ +++
Associated
InstallationGearForm
Amountof
Subscription
AmountofInformation
Displayed
MaintenanceTime
MeanTimeRepair
PartsCost
Interpolation
InstallationTime
Importance:
5High,1Low
HOWs-System
Objectives(DDPs)
Numberofuser
screens
Numberofitemsper
screen
Sizeofdevice
ConfiguraitonTime
InformationUpdate
Rate
Amountof
Warning/Error
ResponsiveTime
SignalStrength
++ +++++
RepairTime
WHATs - Stakeholder Requirements
++ ++ ++
++++
Key
Strong Positive Correlation +++
Medium Positive Correlation ++
Weak Positive Correlation +No correlation
Strong Negative Correlation -
Medium Negative Correlation - -
Weak Negative Correlation - - -
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Objective Hierarchy
Operational O bjectives
Operational P erformance
Objectives
S ystem T ime Objectives
Info Acces s T ime < 30 sec
R esponse T ime < 3 sec
Info Update Time < 1 min
Availability Objectives
MTB F 1 2 min
Maint. Time < 30 min
between 2am and 3am
R epair T ime < 30 min
User C onfig Time < 30 sec
L ife C ycle min 15 yrs
C ost Objectives
S ubscription < $10
P hysical O bjectives
Operation within P hysic alS pec.of Nav. S ystem
(brand, model T B D)
S tandards a nd P rotocols
C ompliance with FC C
R egulations for WirelessDevices
Operation within S ame S td. &
P rotocol of Nav S ys.
(brand, model T B D)
C ommunication through
C ellular Medium (wireles s
Medium TBD)
Integration with C urrent
Nav. S ys. within 1 Y ear
of Partner Agreement
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System Requirements
The functional requirements in this section were derived from the use cases and QFD.
Functional Requirements
Input Requirements The system shall accept an activation request from a driver. The system shall accept an activation request from a content provider. The system shall accept a profile modify request from a driver. The system shall accept a profile modify request from a content provider. The system shall accept a termination request from a driver. The system shall accept a termination request from a content provider. The system shall accept a location notification from a driver. The system shall accept a weather alert notification from a content provider. The system shall accept a road conditions notification from a content provider. The system shall accept a weather hazard notification acknowledgement from a driver. The system shall accept an alternative route request from a driver. The system shall accept a traffic alert notification from a content provider. The system shall accept a traffic conditions notification from a content provider. The system shall accept a traffic jam notification acknowledgement from a driver. The system shall accept a service request from a driver. The system shall accept a service request from a content provider. The system shall accept a service alert acknowledgement from a maintainer. The system shall accept a diagnostics mode request from a maintainer. The system shall accept a self-test request from a maintainer. The system shall accept a self-test request from an installer. The system shall accept a configuration change request from a maintainer. The system shall accept a configuration change request from an installer. The system shall accept a log update request from a maintainer. The system shall accept a log update request from an installer. The system shall accept a normal mode request from a maintainer. The system shall accept a normal mode request from an installer. The system shall accept a normal operation notification acknowledgement from a driver. The system shall accept a normal operation notification acknowledgement from a content
provider. The system shall accept an installation request from a driver. The system shall accept an installation request from a content provider. The system shall accept an installation alert acknowledgement from an installer. The system shall accept an installation mode request from an installer.
Output Requirements The system shall provide an activation response to a driver. The system shall provide an activation response to a content provider. The system shall provide a profile modify response to a driver. The system shall provide a profile modify response to a content provider. The system shall provide a termination response to a driver. The system shall provide a termination response to a content provider. The system shall provide a location acknowledgement to a driver. The system shall provide a weather alert notification acknowledgement to a content
provider. The system shall provide a road conditions notification acknowledgement to a content
provider. The system shall provide a weather hazard notification to a driver.
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The system shall provide an alternative route response to a driver. The system shall provide a traffic alert notification acknowledgement to a content
provider. The system shall provide a traffic conditions notification acknowledgement to a content
provider. The system shall provide a traffic jam notification to a driver. The system shall provide a service acknowledgement to a driver. The system shall provide a service acknowledgement to a content provider.
The system shall provide a service alert to a maintainer. The system shall provide a diagnostics mode response to a maintainer. The system shall provide a self-test response to a maintainer. The system shall provide a self-test response to an installer. The system shall provide a configuration change response to a maintainer. The system shall provide a configuration change response to an installer. The system shall provide a log update acknowledgement to a maintainer. The system shall provide a log update acknowledgement to an installer. The system shall provide a normal mode response to a maintainer. The system shall provide a normal mode response to an installer. The system shall provide a normal operation notification to a driver. The system shall provide a normal operation notification to a content provider. The system shall provide an installation acknowledgement to a driver. The system shall provide an installation acknowledgement to a content provider. The system shall provide an installation alert to an installer. The system shall provide an installation mode response to an installer.
Interface Requirements The navigation system (specific brand and model TBD) shall provide the system external
interfaces. The system shall integrate with the navigation system (specific brand and model TBD)
internal interfaces.
System-wide Requirements
Suitability Requirements Accessing the required information shall take less than 30 seconds and less than 4 user
screens. The number of items per screen shall be such that it takes the user less than 5 seconds
to see all of them. The system shall be easily configured within 30 seconds for driver use. The system shall have a MTBF of greater than 1 year. The design goal is 2 years.
Failure is defined to be a complete inability to provide traffic updates. All system warnings or error messages shall fit within system screen. Response time from button select to screen output shall be less than 3 seconds. User set-up time shall take less than 10 minutes. Maintenance on system shall occur between 2am and 3am daily and shall take less than
one-half hour. Repair time of system unit is limited to 30 minutes before user is notified that repair time
must be extended.
Physical Requirements The system shall operate within the physical specifications of the navigation system
(specific brand and model TBD).
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Technology Requirements The road, traffic, and weather conditions for the requested location shall be current as of
the previous 1 minute.
Cost Requirements The system operational costs shall be $10 a month through a subscription plan.
Standards and Protocols The system shall support the same standards and protocols as navigation system
(specific brand and model TBD). The system shall comply with FCC regulations for wireless devices. The system shall communicate through cellular (specific wireless medium TBD).
Schedule Requirements by Phase The system shall have an expected life of at least 15 years. The system shall integrate with existing navigation systems within 1 year of partner
agreement.
Supportability and Maintenance The system shall provide sparing of monitoring site equipment. The system shall provide training for maintenance personnel.
Functional Architecture
Shown on the next page is the functional architecture using an IDEF0 A1 diagram
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Risks
Item Severity Risk DescriptionPrimaryImpact Mitigation Plan
1 High Timeliness of content providerdata
Performance Perform modeling and simulationof response times from content
provider systems. Prototype withcontent providers.
2 Medium Development of common set ofdiagnostic tools to maintain
system and co-operability withcontent provider and selected
navigation systems withinallocated time.
Maintanence Involve maintenance team intechnical discussions with
selected navigation systemmakers and content provider.
3 Medium Interfaces for selectednavigation systems may bemuch different adding to
design and material costs.
Integration Periodic Technical InterchangeMeetings (TIMs) to discuss
integration issues.
4 Medium Cost risk will increase time andeffort to design different
interfaces for variousnavigation systems.
Cost Periodic TIMs to discussintegration issues.
5 Low Integration with multiplenavigation systems.
Integration Define set of interfaces (hw/sw)to conform to leading navigationsystems. Periodic TIMs to discuss
integration issues.
6 Low Cooperation and collaborationneeded from navigation system
manufacturers.
Integration Periodic TIMs to discussintegration issues.