Systems Engineering Guidebook for ITS - Example Project 1 - Adding Field Elements to an Existing System

4.11.1 Example Project 1 - Adding Field Elements to an Existing System

[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
Feasibility Study	None				Completed and approved as part of the original project.
R Planning	Low	R Risk mgmt R Config mgmt	R Ensure that the plan[s] is up to date and still applicable.	R Changes in staff, stakeholders or institutions, construction, or vendor that may have occurred between the time of the original development and the deployment of these elements. R Vendor defects	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.
Development of a Concept of Operations and Validation Plan	None				Reuse of the Validation Plan
Development of System Level Requirements and Verification Plans	None				Reuse of the Verification Plan
Development of High Level Design/Sub-system Requirements and Verification Plans	None				Reuse of the Verification Plan
Development of Component Level Design	None				COTS product
Hardware/Software Development	None – Low	R Technical Review	R That the host configuration software is operational and can accommodate the additional signs	R Software was not checked out in the original implementation for additional signs	COTS product Original design and implementation included the additional signs
Unit verification	None				Vendor performed
Unit Integration	None				Vendor performed
Sub-system verification	Low	R Technical Review	R Verify that controller, signs, and communications are working	R Defective signs, controller, communications or interface.	Signs and interfaces were checked out and verified at the factory, review of verification data
Sub-system Integration	Low	R Technical Review	R Coordination of integration activities, integration of controller with communications R Integration of signs and controller	R Controller is integrated and working with communications R Integration of signs and controllers	Use of the same interfaces that were used before. Integration issues will only occur if defects occur in manufacturing of the signs.
System verification	Medium	R Technical Review	R Verify that the host software is configured properly and all functionality is verified on all signs. [Regression] testing on the initial signs may be needed	R The added signs, or exercising the host software, uncovered a defect that was not known at time of initial integration and verification	Re-use of original acceptance Verification Plans – 30 signs to verify
Deployment	Medium	R Technical Review	R How the signs will be deployed R The resources needed R Normal construction issues	R Deployment in a timely manner R Lack of resources to deploy the 30 signs.	Per the Deployment Plan
Validation	None				Validation on original project
Operations & Maintenance	Low	R Conf. Mgt.	R Synchronize the new system configuration with any updates to software, patches, user manuals, and fixes with documentation	R Loss of the alignment of the documentation with the physical configuration of the system will provide a loss in system integrity.	Update user’s manuals, as-builds, and software documentation if needed.