Systems Engineering for Intelligent Transportation Systems

2 Why Use Systems Engineering?

2.1 Value of Systems Engineering

Although ITS projects come in many shapes and sizes, they all use technology (computers, communications, sensors, etc.) and frequently include the exchange of information, either within a system or between systems. The technology and integration that sets ITS projects apart also creates challenges for the ITS project manager. What every ITS project manager wants is a successful result at the end of the project, with "success" measured by:

• how well the implementation satisfies the needs of the people who use it, and
• how closely the project stayed within the budgeted cost and schedule.

Systems engineering reduces the risk of schedule and cost overruns and increases the likelihood that the implementation will meet the user's needs. Other benefits include:

• improved stakeholder participation
• more adaptable, resilient systems
• verified functionality and fewer defects
• higher level of reuse from one project to the next, and
• better documentation.

These assertions have been supported by several studies that have shown that good systems engineering results in better cost and schedule performance. Studies have been performed by the International Council of Systems Engineering (INCOSE)¹, Boeing², and IBM³, among others. Figure 1 shows the results of an INCOSE study that collected both planned and actual project and systems engineering cost data for 44 projects. The survey indicated that investing in systems engineering did improve project cost performance. The responses indicated a 50% overrun on average without systems engineering and a clear trend toward better cost performance results with systems engineering.

Figure 1: Systems Engineering Improves Project Cost Performance

2.2 US DOT Policy

US DOT recognized the potential benefit of the systems engineering approach for ITS projects and included requirements for a systems engineering analysis in the FHWA Rule/FTA Policy that was enacted on January 8, 2001. The Rule/Policy requires a systems engineering analysis to be performed for ITS projects that use funds from the Highway Trust Fund, including the Mass Transit Account. As shown in an excerpt from the Rule in Figure 2, the Rule/Policy actually specifies seven requirements that the systems engineering analysis must include at a minimum.

Figure 2: FHWA/FTA Systems Engineering Analysis Requirements

The Rule/Policy allows each project sponsor to use a systems engineering approach that is tailored to fit the needs of each ITS project. As you will see in the following chapters, the systems engineering approach is actually broader than the seven specific requirements identified in the Rule/Policy. If you implement a good systems engineering process, you will meet or exceed the specific systems engineering analysis requirements identified in the Rule/Policy.

The FHWA Division and FTA Regional Offices determine how the systems engineering analysis requirements in the Rule/Policy should be applied to ITS projects in each region and how compliance should be demonstrated by each project sponsor. Federal oversight is provided based on oversight requirements defined in the stewardship agreements with each state. Several states have established checklists that prompt project sponsors to consider the systems engineering analysis requirements as part of the project development process, as shown in Figure 3.⁴ Contact the ITS specialist in your FHWA Division Office or FTA Regional Office for more information.

Figure 3: Examples of Systems Engineering Analysis Requirements Checklist

Note that each organization may establish its own systems engineering process requirements that satisfy the requirements of the Rule/Policy, as Florida DOT did with its Systems Engineering Management Plan (see http://www.floridaits.com/SysEng.html).