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Systems Engineering for Intelligent Transportation Systems

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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:

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:

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.

As systems engineering effort increases as a percentage of project cost, project cost overruns decrease.  Based on relatively few data points, it appears that an optimum is reached when systems engineering costs are about 20% of project costs.

Figure 1: Systems Engineering Improves Project Cost Performance

2.2 US DOT Policy

Rule/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.

Text Box:  23 CFR 940.11 Project implementation. (a) All ITS projects funded with highway trust funds shall be based on a systems engineering analysis. (b) The analysis should be on a scale commensurate with the project scope. (c) The systems engineering analysis shall include, at a minimum: (1) Identification of portions of the regional ITS architecture being implemented (or if a regional ITS architecture does not exist, the applicable portions of the National ITS Architecture); (2) Identification of participating agencies' roles and responsibilities; (3) Requirements definitions; (4) Analysis of alternative system configurations and technology options to meet requirements; (5) Procurement options; (6) Identification of applicable ITS standards and testing procedures; and (7) Procedures and resources necessary for operations and management of the system.

Figure 2: FHWA/FTA Systems Engineering Analysis Requirements

Rule/Policy.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.

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.

Text Box: In California, a Systems Engineering Requirements Form, or SERF, must be completed by the project sponsor at project initiation.  This form, included in the Caltrans Local Assistance Procedures Manual, includes one question for each of the seven systems engineering requirements in Rule 940.11.  The SERF checklist is a streamlined form that is only one or two pages long, but it is enough to ensure that each project sponsor will address the systems engineering requirements of the rule.  Virginia DOT has also implemented a Systems Engineering and Architecture Compliance (Rule 940) checklist for use in Northern Virginia.  Many other states are implementing similar forms.

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).


1Eric Honour, "Understanding the Value of Systems Engineering", 2004.
2John D. Vu, "Software Process Improvement Journey: From Level 1 to Level 5", 2001.
3Bruce Barker, IBM Commercial Products, 2003.
4The SERF is available at www.dot.ca.gov/hq/LocalPrograms/lam/lapm.htm. The Virginia DOT checklist is available at www.vdot-itsarch.com/nova/docs/rule940checklist.doc.

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