Use Model Systems Engineering (SE) Documents for Deployment of Adaptive Signal Control Technology Systems

Systems Engineering guidance developed through lessons learned in national deployments of Adaptive Signal Control Technology systems

Date Posted
10/01/2014
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Identifier
2013-L00643

Lessons Learned

The purpose of this document is to guide the user through the process of developing SE documents for assessment and selection of adaptive signal control technology (ASCT) systems. This document is the result of best practices observed through many case studies and provides a structure within which you can examine your current operation (or the operation you expect to have within the near future), assess whether or not adaptive control is likely to address your issues, and then decide what type of adaptive control will be right for you. Templates are also provided for the development of the SE documents that are appropriate for your situation. There are instructions on how to select appropriate answers to questions, how to select statements from the examples that are provided, and what additional information you need to gather and include in the documents. This may lead you to prepare a set of requirements and a specification against which vendors may propose a solution; or it may lead you to identify one system that is particularly suitable for your needs. It may also lead you to the realization that you are not yet prepared or capable of operating an ASCT system.



The focus of this guidance is to develop documents that will enable deployers to be more effective with future decisions to procure an ASCT system that is currently available from a vendor. It does not provide sufficient guidance to develop procurement documents for the development of a custom-built ASCT system. That would require much more detailed specification of subsystems, physical equipment and user interfaces. Some of the lessons learned throughout this guide help users to:

  • Use proven criteria to decide if adaptive signal control is right for traffic conditions in the location being considered. Agencies needs criteria to help them make decisions about whether adaptive signal control is right for their situation. All criteria should be considered carefully.
  • Use appropriate documentation to initiate ASCT development. Appropriate system development documentation is needed to guide an ASCT project including development of the concept of operations, system requirements, validation plan and verification plan. Templates based on experience and lessons learned are also provided for each of these documents in the appendices of this guide.
  • Provide information in the ASCT ConOps that helps to define the system at a high level. This information helps to define the work and may include:
    • Getting stakeholder agreement to describe how the system is to be operated, who is responsible for what, and what the lines of communication are
    • Defining the high-level system concept to enable evaluation of alternatives
    • Defining the environment in which the system will operate
    • Deriving high-level requirements, especially user requirements
    • Providing scenarios and criteria to be used for validation (via the Validation Plan) of the completed system
  • Determine the types of requirements that would best serve the scope of a project. Organizing requirements into manageable categories can help to develop, implement and test requirements in a more effective manner. Some categories to consider include functional, performance, non-functional, enabling, constraints, interface, and data requirements.
  • Consider using proven verification planning to help manage ASCT project efforts. For even moderately complex systems, the following three levels of verification planning documents are recommended:
    • A plan to initially lay out the specific verification effort
    • A detailed verification plan that defines a detailed mapping of the requirements to verification cases
    • A report on the results of the verification activities
  • Consider using proven validation planning to help manage ASCT project acceptance. Validation documents plan, describe, and record the activities which validate that the system being built meets the user needs and scenarios developed in the Concept of Operations. Usually, for even moderately complex systems, the following three levels of validation documents are prepared:
    • A plan to initially lay out the specific validation effort
    • The user's/operator's manual and/or a validation plan that defines the detailed operational procedures
    • A report on the results of the validation activities
  • Reference documentation previously developed for other ASCT projects to get ideas or to reuse information that pertains to these systems. This Model Systems Engineering Documents for ASCT guide was developed for those planning to implement ASCT and it includes example operational scenarios, user needs and requirements. Readers are encouraged to reuse the information provided in the guide that is relevant to their ASCT projects.

The SE process was defined to provide managers with the tools to organize, document, and control the progress of systems projects. This guide, based on best practices and lessons learned from ASCT deployments, provides SE guidance specifically tailored for ASCT projects and offers detailed examples for key project documentation. This guide is a must read for managers that want to control costs, meet schedules, and achieve desired system quality for ASCT projects.