U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
California Division
[Please note that the solution given here is for this example only. Other viable solutions may be possible and each must be evaluated for a given project.]
A $10 million project to add 30 full matrix changeable message signs [assuming $330,000 per sign] to an existing system that had five identical signs already deployed. No changes are needed to the existing central or field equipment. The system was initially designed to accommodate these additional signs so no additional software is needed. Assumptions are: 1] the communications and power for the signs have already been deployed under a previous construction project, 2] the initial system has been completed and the system is working, 3] the contractor will deploy the signs, poles and foundations, controllers, and wire the controllers into the signs, 4] the agency will add configuration information about the signs at the central computer, and 5] the construction costs have been included in the cost of the signs.
In this example, even though this is a high dollar amount, little systems engineering is needed because the risks are low and no decisions or trade studies are required. This same example can be applied to many current ITS projects such as adding: field masters and traffic signals to a traffic signal control system, cameras to an existing surveillance system, or detectors to an existing detection system. Adding elements to existing systems which do not require additional design, coding, or development [other than the construction design needed for the signs and controllers at each location] would require the minimum amount of formal systems engineering. However, it is recommended that updates to existing plans and reviews be performed to ensure that the original design and implementation is not adversely affected as a result of adding the elements.
Process Step | Estimated Level of Effort | Check list of supporting activities | Check list of issues | Check list of risks | Examples | ||||||||||||
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Feasibility Study |
None |
Completed and approved as part of the original project. |
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Low |
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Update of the Deployment Plan and Integration Plans. Construction risks were low and no changes to the designs needed. The system can be configured to accommodate the additional signs. Vendor has good internal processes. The sign is his standard product. |
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Development of a Concept of Operations and Validation Plan |
None |
Reuse of the Validation Plan |
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Development of System Level Requirements and Verification Plans |
None |
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Reuse of the Verification Plan |
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Development of High Level Design/Sub-system Requirements and Verification Plans |
None |
Reuse of the Verification Plan |
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Development of Component Level Design |
None |
COTS product |
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Hardware/Software Development |
None – Low |
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COTS product Original design and implementation included the additional signs |
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Unit verification |
None |
Vendor performed |
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Unit Integration |
None |
Vendor performed |
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Sub-system verification |
Low |
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Signs and interfaces were checked out and verified at the factory, review of verification data |
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Sub-system Integration |
Low |
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Use of the same interfaces that were used before. Integration issues will only occur if defects occur in manufacturing of the signs. |
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System verification |
Medium |
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Re-use of original acceptance Verification Plans – 30 signs to verify |
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Deployment |
Medium |
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Per the Deployment Plan |
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Validation |
None |
Validation on original project |
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Operations & Maintenance |
Low |
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Update user's manuals, as-builds, and software documentation if needed. |