Worldwide Rescue Locator Device WoRLD. Requirements “Needs” Statement "According to the National Center for Mission and Exploited Children for the year

Worldwide Rescue

Locator DeviceWoRLD

Requirements “Needs” Statement"According to the National Center for Mission and Exploited Children for the year 2000, there were over 750,000 reports of missing children - roughly 2,100 children per day.”*

We will develop a system to

increase the recovery rate

of these children.*Source: http://www.ncmec.org/download/ar_2000.pdf

Requirements Elicitation Process

• We Developed Case Scenarios– Child wearing device 24x7 to various activities– Operation during abduction– Non-family child abduction– Operation during non-abduction

• We Used Functional Scenarios– Tracking operations– Reporting operations– Processes and procedures– Hardware, software– Performance

• We Performed Similar System Examinations– Cadillac OnStar® System

• OnStar add-on services

– Acura Navigation System– Volvo Navigation System– Lo-Jack Anti-Theft System

• We Solicited Stakeholder Inputs (Parental Survey)– 10 question survey to 5 mothers of children

Used a broad array of elicitation techniques . . .

Requirements Results• Developed ~90 unique requirements• Developed 6 functional areas (15 sub-functions)

–Power Management•Idle

•Activated

–Communications•Transmit/Receive EOC-MU

•EOC-Police

•EOC-Parents

–Tracking•Acquire GPS signals

•Calculate location

–Data Storage•Store location at EOC

•Store location in Mobile Unit

–Maintenance•EOC Maintenance

•Mobile Unit Maintenance

–Performance•Reliability

•Affordability

•Size/Weight

•Legal Compliance

Architectures: Requirements Mapping

Requirements Navigation System

Power Mgmt

Wearing of Device

Notifi-cation

Comm Ops Center

The WoRLD system shall map coordinates to area mapping systems.

The mobile unit shall be operated and worn continuously

The mobile unit shall self-activate

Operate in low power standby mode for a period of 72 hours

Establish a robust communication infrastructure to facilitate interstate cases and exchanges

The mobile unit shall report its system health status

The system shall transfer coordinate information to local, state, federal law enforcement agencies, or parents.

The mobile unit available in NFT five different sizes.

The mobile unit will be concealable.

The navigation data should promote good ranging properties, signal hiding and immunity to jamming.

The WoRLD system shall not transmit coordinate information until activation.

The EOC shall be capable of interrogating transmit devices.

The mobile unit will be difficult to remove.

The mobile unit designed with anti-tamper measures

The WoRLD shall be responsive to local, state and federal laws.

ArchitecturesFunctional System Areas Architecture Alternatives

Navigation

SystemGPS LORAN Orbcomm

Power

ManagementSolar Batteries Kinetic

Wearing of

DeviceImplant Obvious

ExternalHidden

ExternalNotification Operator Auto-

notificationDistance Trigger

Communications Cell-Analog

Cell Digital

Ops Center Central Distributed

* Total number of possible architectures: 3x3x3x3x2x2 = 324

Architectures: Alternatives• The 5 chosen architectures explore the

trade-space• Low, Mid, High Cost• Low, Mid, High Performance• High Value Option

• Architecture choices are based upon the following • Use Case Scenarios• Questionnaires• Student research of relevant technologies (lo-jack, LORAN,

Cell Analog, GPS)• Past experience of group

Architectures: Considerations…

Functional System Areas Architecture AlternativesNavigation

System

GPS

(High Cost)

(High Performance)

LORAN

(Mid Cost)

(Low Performance)

Orbcomm

(Mid Cost)

(High Performance)

Power

Management

Solar

(Mid Cost)

(Mid Performance)

Batteries

(Low Cost)

(High Performance)

Kinetic

(High Cost)

(Low Performance)

Wearing of Device Implant

(High Cost)

(High Performance)

Obvious External

(Low Cost)

(High Performance)

Hidden External

(Mid Cost)

(High Performance)

Notification Operator

(High Cost)

(High Performance)

Auto-notification

(Mid Cost)

(Mid Performance)

Distance Trigger

(Low Cost)

(Low Performance)


(Low Cost)

(High Performance)

Cell Digital

(High Cost)

(Mid Performance)

Ops Center Central

(Mid Cost)

(High Performance)

Distributed

(High Cost)

(High Performance)

Arch. 1 High Cost/High Performance

Functional System Areas

Chosen Alternatives

Navigation System

GPS LORAN Orbcomm

Power Management

Solar Batteries Kinetic

Wearing of Device Implant Obvious Hidden External

Notification Operator Auto-notification Distance Trigger

Communications Cell-Analog Cell Digital


Arch. 2 Low Cost/High Performance


Chosen Alternatives

Navigation System

GPS LORAN Orbcomm

Power Management






Arch. 3 Mid Cost/High Performance


Chosen Alternatives

Navigation System

GPS LORAN Orbcomm

Power Management






Arch. 4 High Cost/Mid Performance


Chosen Alternatives

Navigation System

GPS LORAN Orbcomm

Power Management






Arch. 5 Mid Cost/Mid Performance


Chosen Alternatives

Navigation System

GPS LORAN Orbcomm

Power Management






Expert Choice: Values toward Goal

1: Power Management

2: Performance of Device in Different Locations

3: Performance under Certain Scenarios

4: RMA

5: Human Factors

6: Performance under 3 activation scenarios

Expert Choice: Weighting Criteria

Expert Choice: Trade Analysis

Arch Cost Perf

5 Mid Mid

2 Low High

1 High High

4 High Mid

3 Mid High

Overall

Inconsistency: 0.02

Expert Choice: Sensitivity• Analysis indicates Architecture Performance is

Sensitive to following Evaluation Criteria– Power

• Change of importance from 0.4 to 0.5 makes Architecture 2 preferred alternative vice Architecture 5

• More important Power becomes, less desirable Architecture 5 becomes

– Performance of Device in Different Locations• The more important this criteria becomes, the less desirable Architecture

5 becomes, however there is very little change in other Architectures

– Performance Under Certain Scenarios• Really Changes Outcome of Preferred Alternative

– Increase from 0.2 to 0.3 makes order 2, 5, 1– Increase from 0.2 to 0.4 makes order 2, 4, 1, 5– Increase from 0.2 to 0.5 makes order 4, 2, 1, 5

– Performance Under Different Activations• Increase of importance from 0.05 to .2 makes Architecture 1 the

preferred alternative (the only time this occurs)

Most Sensitive

Expert Choice: Pros/Cons

Arch. Pros Cons1 •Device is hard to remove

•Good power management•Good protection against parental abduction

•High cost•Very low user acceptance•Upgrades would be difficult and invasive

2 •Low cost•Good power management•Performs well when child gets lost and self activates

•High maintenance•Device is larger in size and easier to remove•Higher maintenance needs

3 •Low cost•Responds well to Call Center activation•High performance outside of buildings

•High maintenance•Device has low performance inside and over long distances•Performs lower during non-parental abductions

4 •Low scheduled and unscheduled maintenance•Device is small and difficult to remove•Waterproof

•High cost•Device upgrades would be difficult and invasive•LORAN technology is becoming obsolete

5 •High system reliability•Low scheduled and unscheduled maintenance•High user acceptance

•Difficult to upgrade•Bad power management when in idle state•Performed poorly in most abduction scenarios

Lifecycle Cost Basis of Estimate

• Estimate based on Fairfax County, VA– Approximately 250,000 children in the county,

estimate was scaled to 100,000 children.

• Estimate based on 5-year Lifecycle– 1st year slated for development of system and

training of personnel– Years 2 through 5 the system was operational

• Approximately 2,000 children missing each day, or roughly 7 per day for area the size of Fairfax county– Modeled ~ 100 calls per day across all

scenarios, assumed at least 7 would be “emergency calls”

Arch Initial

Est.

Estimated

Cost

1 High $303M

2 Low $154M

3 Mid $154M

4 High $328M

5 Mid $245M

Final Analysis: Pros/Cons• Top 2 Alternatives: Architectures 2 and 5

– Mixed Pros & Cons with Each– Even trade offs

• Arch-2: 0.246• Arch-5: 0.252

Different Locations

Certain Scenarios

Under 3 Activation Scenarios

Final Analysis: CostEffectiveness vs Cost for WoRLD System

Architectures

0

0.05

0.1

0.15

0.2

0.25

0.3

0 50 100 150 200 250 300 350

Cost (millions)

Eff

ec

tiv

en

es

s

Architecture 1

Architecture 2

Architecture 3

Architecture 4

Architecture 5

1

4

2

5

3

Good

Fair

Poor

Best Performance for the money . . .

Final Analysis: Ranking• Architecture 2: Highest “Value Index”Arch Cost Trade

Value

Value

Index

2 Low - $154M .246 1.605 Mid - $245M .252 1.03

1 High - $303M .233 0.77

3 Low – $154M .088 0.57

4 High - $328M .181 0.55

Functional System Areas Chosen Alternative

Navigation System Orbcomm

Power Management Batteries

Wearing of Device Obvious

Notification Auto-Notification


Ops Center Central

Architecture 2 -

Class Exercise

Assignment: Architect a solution to the problems caused by the potential installation of XYZ Cellular Corp’s Base Station.

1. Create a problem(s)/need(s) statement

2. Decompose into a basic requirement set (~10-20)

3. Allocate requirements across a Functional set (~5)

4. Develop design alternatives for each function (~3)

5. Develop alternate system architectures (~3)

6. Evaluate alternatives vs. criteria (~5)

7. Select & recommend a preferred alternative

Documents

Worldwide Rescue Locator Device WoRLD. Requirements “Needs” Statement "According to the National Center for Mission and Exploited Children for the year