Determining the overall complexity of the project and the level of risk is critical to selecting the best procurement approach. The Guide to Contracting ITS Projects defines the following four categories of overall project complexity and risk:

1. Straightforward in terms of complexity and low overall risk (i.e. expansion of existing systems or adding additional field devices, such as CCTV or DMS)
2. Moderately complex and moderate overall risk (i.e. implementation of a computerized signal system)
3. Complex and high overall risk (i.e. replacement of existing TMC software with the addition of new system functionality)
4. Extremely complex with very high overall risk (i.e. New TMC system implementation including field devices, interfaces to internal/external systems etc.)

Six factors, including level of new deployment, scope and breadth of technologies, interfaces to other systems, technology evolution, requirements fluidity, and institutional issues are used to classify projects into the appropriate project category (1 through 4). The following observations are made with regard to the role of these six factors in assessing a project’s overall complexity and risk:

• Determine the level of new deployment. The level of new deployment typically has a significant impact on the overall complexity and risk of an ITS project. The straightforward or least risky projects (category 1) include little to no new development, as in the case of commercial off the shelf (COTS) software and/or hardware. Projects requiring entirely new software development (category 4) are the most risky and complex.
• Define the scope and breadth of technologies. Projects that involve the application of proven, well-known, and commercially available technology and that are smaller in scope (i.e. involving a single technology implementation, such as DMS or CCTV) are characterized as straightforward and low risk (category 1). At the other extreme, category 4 projects involve new software development combined with new hardware configurations, the implementation of a broad scope of technologies and may require multiple phases for implementation.
• Determine the interfaces to other systems. The characteristics that describe this factor are based on the number of major subsystems as well as the number of and complexity of existing and new system/database interfaces that will be included in an ITS project. Straightforward projects are single system (or are a small expansion of an existing system deployment), and system interfaces are well known. The higher project categories are characterized by an increasing number of subsystems and interfaces to new and/or existing systems and databases.
• Assess technology evolution. The characteristic that describes this factor are based on an agency's "perceived need" to account for the evolution of technology. For straightforward (category 1) projects the need to account for technology evolution is minor, whereas for extremely complex, category 4 projects, it is a major issue.
• Determine fluidity of requirements. System requirements for category 1 projects are very well defined and are unlikely to change over time. As the complexity and risk increases, the addition of new system functionality requires more attention to requirements management. For extremely complex projects, systems requirements are not well defined and are very likely to change over time.
• Assess institutional issues. As the need for institutional coordination increases, so does the level of complexity and risk associated with a project. Straightforward projects generally have minor institutional issues, as they involve a single agency and are typically internal to a department within that agency. At the other extreme, category 4 projects involve coordination among multiple agencies, departments and disciplines.

When assessing complexity and risk, the two factors that should be given greater weight include level of new development and fluidity of requirements, as these two factors are best suited to capturing the greater development risk associated with the higher project categories. Some projects may be difficult to classify, as they do not neatly fit into a single project category. In these cases, the selection of the higher project category is recommended.

When the ITS project category has been defined, this information will be used, along with the defined agency capability level to select an appropriate systems engineering process and initial procurement package(s). These steps of the decision model are designed to create an efficient and reliable procurement process. This increased efficiency can result in cost savings for agencies in the procurement of ITS. Moreover, by enabling agencies to choose the most appropriate procurement package, the Decision Model facilitates the ultimate success of the ITS deployment.